While working with strings, it is essential to keep the character set of the client connection in mind. If there is a mismatch between the character sets of the stored data and that of the client connection, the output results for string columns are automatically re-encoded, both when data are sent from the client to the server and when they are sent back from the server to the client. The character set NONE is a special character set in Firebird.

It can be characterized such that each byte is a part of a string, but the string is stored in the system without any clues about what constitutes any character: character encoding, collation, case, etc. are simply unknown. It is the responsibility of the client application to deal with the data and provide the means to interpret the string of bytes in some way that is meaningful to the application and the human user. Data in OCTETS encoding are treated as bytes that may not actually be interpreted as characters.

OCTETS provides a way to store binary data, which could be the results of some Firebird functions. The database engine has no concept of what it is meant to do with a string of bits in OCTETS , other than just store it and retrieve it. Again, the client side is responsible for validating the data, presenting them in formats that are meaningful to the application and its users and handling any exceptions arising from decoding and encoding them.

Each character set has a default collation sequence COLLATE that specifies the collation order. Usually, it provides nothing more than ordering based on the numeric code of the characters and a basic mapping of upper- and lower-case characters. If some behaviour is needed for strings that is not provided by the default collation sequence and a suitable alternative collation is supported for that character set, a COLLATE collation clause can be specified in the column definition.

A COLLATE collation clause can be applied in other contexts besides the column definition. If output needs to be sorted in a special alphabetic sequence, or case-insensitively, and the appropriate collation exists, then a COLLATE clause can be included with the ORDER BY clause when rows are being sorted on a character field and with the GROUP BY clause in case of grouping operations.

For a case-insensitive search, the UPPER function could be used to convert both the search argument and the searched strings to upper-case before attempting a match:. For strings in a character set that has a case-insensitive collation available, you can simply apply the collation, to compare the search argument and the searched strings directly.

The following table shows the possible collation sequences for the UTF8 character set. Collation works according to the position of the character in the table binary. Added in Firebird 2. Collation works according to the UCA algorithm Unicode Collation Algorithm alphabetical. Case-insensitive collation, works without taking character case into account. Case-insensitive, accent-insensitive collation, works alphabetically without taking character case or accents into account.

In Firebird earlier than version 2. Multi-byte character sets and compound indexes limit the size even further. The maximum length of an indexed string is 9 bytes less than that quarter-page limit. The table below shows the maximum length of an indexed string in characters , according to page size and character set, calculated using this formula.

CREATE DATABASE , Collation sequence , SELECT , WHERE , GROUP BY , ORDER BY. CHAR is a fixed-length data type.

If the entered number of characters is less than the declared length, trailing spaces will be added to the field. Generally, the pad character does not have to be a space: it depends on the character set. For example, the pad character for the OCTETS character set is zero. The full name of this data type is CHARACTER , but there is no requirement to use full names and people rarely do so. A valid length is from 1 to the maximum number of characters that can be accommodated within 32, bytes.

VARCHAR is the basic string type for storing texts of variable length, up to a maximum of 32, bytes. The stored structure is equal to the actual size of the data plus 2 bytes where the length of the data is recorded.

All characters that are sent from the client application to the database are considered meaningful, including the leading and trailing spaces.

However, trailing spaces are not stored: they will be restored upon retrieval, up to the recorded length of the string. The full name of this type is CHARACTER VARYING. Another variant of the name is written as CHAR VARYING. In all other respects it is the same as CHAR. A similar data type is available for the variable-length string type: NATIONAL CHARACTER VARYING. BLOB s Binary Large Objects are complex structures used to store text and binary data of an undefined length, often very large.

Specifying the BLOB segment is throwback to times past, when applications for working with BLOB data were written in C Embedded SQL with the help of the gpre pre-compiler. Nowadays, it is effectively irrelevant. The segment size for BLOB data is determined by the client side and is usually larger than the data page size, in any case. Firebird provides two pre-defined subtypes for storing user data:.

The alias for subtype zero is BINARY. This is the subtype to specify when the data are any form of binary file or stream: images, audio, word-processor files, PDFs and so on. Subtype 1 has an alias, TEXT , which can be used in declarations and definitions. It is a specialized subtype used to store plain text data that is too large to fit into a string type.

A CHARACTER SET may be specified, if the field is to store text with a different encoding to that specified for the database. From Firebird 2. It is also possible to add custom data subtypes, for which the range of enumeration from -1 to , is reserved. Custom subtypes enumerated with positive numbers are not allowed, as the Firebird engine uses the numbers from 2-upward for some internal subtypes in metadata. The maximum size of a BLOB field is limited to 4GB, regardless of whether the server is bit or bit.

The internal structures related to BLOB s maintain their own 4-byte counters. The following operators are supported completely:. Aggregation clauses work not on the contents of the field itself, but on the BLOB ID.

Aside from that, there are some quirks:. concatenates the same strings if they are adjacent to each other, but does not do it if they are remote from each other. By default, a regular record is created for each BLOB and it is stored on a data page that is allocated for it. If the entire BLOB fits onto this page, it is called a level 0 BLOB. The number of this special record is stored in the table record and occupies 8 bytes.

If a BLOB does not fit onto one data page, its contents are put onto separate pages allocated exclusively to it blob pages , while the numbers of these pages are stored into the BLOB record. This is a level 1 BLOB. If the array of page numbers containing the BLOB data does not fit onto a data page, the array is put on separate blob pages, while the numbers of these pages are put into the BLOB record.

This is a level 2 BLOB. FILTER , DECLARE FILTER. The support of arrays in the Firebird DBMS is a departure from the traditional relational model. Supporting arrays in the DBMS could make it easier to solve some data-processing tasks involving large sets of similar data. Arrays in Firebird are stored in BLOB of a specialized type. Arrays can be one-dimensional and multidimensional and of any data type except BLOB and ARRAY. This example will create a table with a field of the array type consisting of four integers.

The subscripts of this array are from 1 to 4. To specify explicit upper and lower bounds of the subscript values, use the following syntax:. A new dimension is added using a comma in the syntax. In this example we create a table with a two-dimensional array, with the lower bound of subscripts in both dimensions starting from zero:. The DBMS does not offer much in the way of language or tools for working with the contents of arrays.

The database employee. fdb , found in the.. If the features described are enough for your tasks, you might consider using arrays in your projects. Currently, no improvements are planned to enhance support for arrays in Firebird. It is not available as a data type for declaring table fields, PSQL variables or parameter descriptions.

It was added to support the use of untyped parameters in expressions involving the IS NULL predicate. An evaluation problem occurs when optional filters are used to write queries of the following type:. This is a case where the developer writes an SQL query and considers :param1 as though it were a variable that he can refer to twice.

The server cannot determine the type of the second parameter since it comes in association with IS NULL. The following example demonstrates its use in practice.

Each named parameter corresponds with two positional parameters in the query. The application passes the parameterized query to the server in the usual positional? in our example. Firebird has no knowledge of their special relation with the first and third parameters: that responsibility lies entirely on the application side.

Once the values for size and colour have been set or left unset by the user and the query is about to be executed, each pair of XSQLVAR s must be filled as follows:.

In other words: The value compare parameter is always set as usual. When composing an expression or specifying an operation, the aim should be to use compatible data types for the operands.

When a need arises to use a mixture of data types, it should prompt you to look for a way to convert incompatible operands before subjecting them to the operation. The ability to convert data may well be an issue if you are working with Dialect 1 data.

When you cast to a domain, any constraints declared for it are taken into account, i. If the value does not pass the check, the cast will fail.

When operands are cast to the type of a column, the specified column may be from a table or a view. Only the type of the column itself is used. For character types, the cast includes the character set, but not the collation. The constraints and default values of the source column are not applied. Keep in mind that partial information loss is possible. For instance, when you cast the TIMESTAMP data type to the DATE data type, the time-part is lost. To cast string data types to the DATE , TIME or TIMESTAMP data types, you need the string argument to be one of the predefined date and time literals see Table 9 or a representation of the date in one of the allowed date-time literal formats:.

It may contain 1 or 2 digits or You can also specify the three-letter shorthand name or the full name of a month in English. A separator, any of permitted characters. Leading and trailing spaces are ignored. These shorthand expressions are evaluated directly during parsing, as though the statement were already prepared for execution.

Thus, even if the query is run several times, the value of, for instance, timestamp 'now' remains the same no matter how much time passes. If you need the time to be evaluated at each execution, use the full CAST syntax.

An example of using such an expression in a trigger:. In Dialect 1, in many expressions, one type is implicitly cast to another without the need to use the CAST function. For instance, the following statement in Dialect 1 is valid:. In Dialect 1, mixing integer data and numeric strings is usually possible because the parser will try to cast the string implicitly. For example,.

In Dialect 3, an expression like this will raise an error, so you will need to write it as a CAST expression:. When multiple data elements are being concatenated, all non-string data will undergo implicit conversion to string, if possible. Creating a domain does not truly create a new data type, of course. If several tables need columns defined with identical or nearly identical attributes, a domain makes sense. Domain usage is not limited to column definitions for tables and views.

Domains can be used to declare input and output parameters and variables in PSQL code. A domain definition contains required and optional attributes. The data type is a required attribute. Optional attributes include:. Explicit Data Type Conversion for the description of differences in the data conversion mechanism when domains are specified for the TYPE OF and TYPE OF COLUMN modifiers. While defining a column using a domain, it is possible to override some of the attributes inherited from the domain.

Table 3. To add new conditions to the check, you can use the corresponding CHECK clauses in the CREATE and ALTER statements at the table level. Often it is better to leave domain nullable in its definition and decide whether to make it NOT NULL when using the domain to define columns. CREATE DOMAIN in the Data Definition Language DDL section. To change the attributes of a domain, use the DDL statement ALTER DOMAIN.

With this statement you can:. If you change domains in haste, without carefully checking them, your code may stop working! When you convert data types in a domain, you must not perform any conversions that may result in data loss. Also, for example, if you convert VARCHAR to INTEGER , check carefully that all data using this domain can be successfully converted.

ALTER DOMAIN in the Data Definition Language DDL section. The DDL statement DROP DOMAIN deletes a domain from the database, provided it is not in use by any other database objects. DROP DOMAIN in the Data Definition Language DDL section. SQL expressions provide formal methods for evaluating, transforming and comparing values. SQL expressions may include table columns, variables, constants, literals, various statements and predicates and also other expressions. The complete list of possible tokens in expressions follows.

Identifier of a column from a specified table used in evaluations or as a search condition. A column of the array type cannot be an element in an expression except when used with the IS [NOT] NULL predicate. An expression may contain a reference to an array member i. The reserved words NOT , AND and OR , used to combine simple search conditions in order to create complex assertions.

Predicates used to check the existence of values in a set. The IN predicate can be used both with sets of comma-separated constants and with subqueries that return a single column.

The EXISTS , SINGULAR , ALL , ANY and SOME predicates can be used only with subqueries. An expression, similar to a string literal enclosed in apostrophes, that can be interpreted as a date, time or timestamp value. Date literals can be predefined literals 'TODAY' , 'NOW' , etc. or strings of characters and numerals, such as ' Declared local variable, input or output parameter of a PSQL module stored procedure, trigger, unnamed PSQL block in DSQL.

A member of in an ordered group of one or more unnamed parameters passed to a stored procedure or prepared query. A SELECT statement enclosed in parentheses that returns a single scalar value or, when used in existential predicates, a set of values.

Operations inside the parentheses are performed before operations outside them. When nested parentheses are used, the most deeply nested expressions are evaluated first and then the evaluations move outward through the levels of nesting. Clause applied to CHAR and VARCHAR types to specify the character-set-specific collation sequence to use in string comparisons. Expression for obtaining the next value of a specified generator sequence. A constant is a value that is supplied directly in an SQL statement, not derived from an expression, a parameter, a column reference nor a variable.

It can be a string or a number. The maximum length of a string is 32, bytes; the maximum character count will be determined by the number of bytes used to encode each character.

Double quotes are NOT VALID for quoting strings. SQL reserves a different purpose for them. Care should be taken with the string length if the value is to be written to a VARCHAR column.

The maximum length for a VARCHAR is 32, bytes. The character set of a string constant is assumed to be the same as the character set of its destined storage.

Each pair of hex digits defines one byte in the string. Strings entered this way will have character set OCTETS by default, but the introducer syntax can be used to force a string to be interpreted as another character set. The client interface determines how binary strings are displayed to the user. The isql utility, for example, uses upper case letters A-F, while FlameRobin uses lower case letters. Other client programs may use other conventions, such as displaying spaces between the byte pairs: '4E 65 72 76 65 6E'.

The hexadecimal notation allows any byte value including 00 to be inserted at any position in the string. However, if you want to coerce it to anything other than OCTETS, it is your responsibility to supply the bytes in a sequence that is valid for the target character set. This is known as introducer syntax. Its purpose is to inform the engine about how to interpret and store the incoming string. In SQL, for numbers in the standard decimal notation, the decimal point is always represented by period.

Inclusion of commas, blanks, etc. will cause errors. Exponential notation is supported. For example, 0. Hexadecimal notation is supported by Firebird 2. Numbers with hex digits will be interpreted as type INTEGER ; numbers with hex digits as type BIGINT. Hex numbers in the range To coerce a number to BIGINT , prepend enough zeroes to bring the total number of hex digits to nine or above.

That changes the type but not the value. When written with eight hex digits, as in 0x9E44F9A8 , a value is interpreted as bit INTEGER. Since the leftmost bit sign bit is set, it maps to the negative range With one or more zeroes prepended, as in 0x09E44F9A8 , a value is interpreted as bit BIGINT in the range The sign bit is not set now, so they map to the positive range This is something to be aware of.

Hex numbers between FFFF FFFF FFFF FFFF are all negative BIGINT. A SMALLINT cannot be written in hex, strictly speaking, since even 0x1 is evaluated as INTEGER. However, if you write a positive integer within the bit range 0x decimal zero to 0x7FFF decimal it will be converted to SMALLINT transparently.

It is possible to write to a negative SMALLINT in hex, using a 4-byte hex number within the range 0xFFFF decimal to 0xFFFFFFFF decimal SQL operators comprise operators for comparing, calculating, evaluating and concatenating values. SQL Operators are divided into four types. Each operator type has a precedence , a ranking that determines the order in which operators and the values obtained with their help are evaluated in an expression.

The higher the precedence of the operator type is, the earlier it will be evaluated. Each operator has its own precedence within its type, that determines the order in which they are evaluated in an expression. Operators with the same precedence are evaluated from left to right. To force a different evaluation order, operations can be grouped by means of parentheses. Arithmetic operations are performed after strings are concatenated, but before comparison and logical operations.

Comparison operations take place after string concatenation and arithmetic operations, but before logical operations. Character strings can be constants or values obtained from columns or other expressions. Combines two or more predicates, each of which must be true for the entire predicate to be true.

Combines two or more predicates, of which at least one predicate must be true for the entire predicate to be true. NEXT VALUE FOR returns the next value of a sequence. SEQUENCE is an SQL-compliant term for a generator in Firebird and its ancestor, InterBase. A step value of 0 returns the current sequence value. A conditional expression is one that returns different values according to how a certain condition is met. It is composed by applying a conditional function construct, of which Firebird supports several.

This section describes only one conditional expression construct: CASE. All other conditional expressions apply internal functions derived from CASE and are described in Conditional Functions. The CASE construct returns a single value from a number of possible ones. Two syntactic variants are supported:.

The simple CASE , comparable to a case construct in Pascal or a switch in C. When this variant is used, test-expr is compared expr 1, expr 2 etc. If no match is found, defaultresult from the optional ELSE clause is returned. If there are no matches and no ELSE clause, NULL is returned. That is, if test-expr is NULL , it does not match any expr , not even an expression that resolves to NULL.

The returned result does not have to be a literal value: it might be a field or variable name, compound expression or NULL literal. A short form of the simple CASE construct is the DECODE function. The first expression to return TRUE determines the result. If no expressions return TRUE , defaultresult from the optional ELSE clause is returned as the result. If no expressions return TRUE and there is no ELSE clause, the result will be NULL.

As with the simple CASE construct, the result need not be a literal value: it might be a field or variable name, a compound expression, or be NULL. NULL is not a value in SQL, but a state indicating that the value of the element either is unknown or it does not exist.

When you use NULL in logical Boolean expressions, the result will depend on the type of the operation and on other participating values. When you compare a value to NULL , the result will be unknown. NULL means NULL but, in Firebird, the logical result unknown is also represented by NULL. It has already been shown that NOT NULL results in NULL.

The interaction is a bit more complicated for the logical AND and logical OR operators:. Up to and including Firebird 2. However, there are logical expressions predicates that can return true, false or unknown. A subquery is a special form of expression that is actually a query embedded within another query.

Subqueries are written in the same way as regular SELECT queries, but they must be enclosed in parentheses. Subquery expressions can be used in the following ways:. To obtain values or conditions for search predicates the WHERE , HAVING clauses. To produce a set that the enclosing query can select from, as though were a regular table or view. Subqueries like this appear in the FROM clause derived tables or in a Common Table Expression CTE.

A subquery can be correlated. A query is correlated when the subquery and the main query are interdependent. To process each record in the subquery, it is necessary to fetch a record in the main query; i. When subqueries are used to get the values of the output column in the SELECT list, a subquery must return a scalar result.

Subqueries used in search predicates, other than existential and quantified predicates, must return a scalar result; that is, not more than one column from not more than one matching row or aggregation.

Although it is reporting a genuine error, the message can be slightly misleading. If P resolves as TRUE, it succeeds. If it resolves to FALSE or NULL UNKNOWN , it fails. A trap lies here, though: suppose the predicate, P , returns FALSE. In this case NOT P will return TRUE.

On the other hand, if P returns NULL unknown , then NOT P returns NULL as well. In SQL, predicates can appear in CHECK constraints, WHERE and HAVING clauses, CASE expressions, the IIF function and in the ON condition of JOIN clauses.

An assertion is a statement about the data that, like a predicate, can resolve to TRUE, FALSE or NULL. Assertions consist of one or more predicates, possibly negated using NOT and connected by AND and OR operators. Parentheses may be used for grouping predicates and controlling evaluation order.

A predicate may embed other predicates. Evaluation sequence is in the outward direction, i. A comparison predicate consists of two expressions connected with a comparison operator. There are six traditional comparison operators:. For the complete list of comparison operators with their variant forms, see Comparison Operators. If one of the sides left or right of a comparison predicate has NULL in it, the value of the predicate will be UNKNOWN. The following query will return no data, even if there are printers with no type specified for them, because a predicate that compares NULL with NULL returns NULL :.

On the other hand, ptrtype can be tested for NULL and return a result: it is just that it is not a comparison test:. When CHAR and VARCHAR fields are compared for equality, trailing spaces are ignored in all cases. The BETWEEN predicate tests whether a value falls within a specified range of two values. NOT BETWEEN tests whether the value does not fall within that range. The operands for BETWEEN predicate are two arguments of compatible data types.

The search is inclusive the values represented by both arguments are included in the search. In other words, the BETWEEN predicate could be rewritten:. When BETWEEN is used in the search conditions of DML queries, the Firebird optimizer can use an index on the searched column, if it is available. The LIKE predicate compares the character-type expression with the pattern defined in the second expression. Case- or accent-sensitivity for the comparison is determined by the collation that is in use.

A collation can be specified for either operand, if required. If the tested value matches the pattern, taking into account wildcard symbols, the predicate is TRUE. If the search string contains either of the wildcard symbols, the ESCAPE clause can be used to specify an escape character. Actually, the LIKE predicate does not use an index.

So, if you need to search for the beginning of a string, it is recommended to use the STARTING WITH predicate instead of the LIKE predicate. Search for tables containing the underscore character in their names.

The STARTING WITH predicate searches for a string or a string-like type that starts with the characters in its value argument.

The search is case-sensitive. When STARTING WITH is used in the search conditions of DML queries, the Firebird optimizer can use an index on the searched column, if it exists.

It can be used for an alphanumeric string-like search on numbers and dates. However, if an accent-sensitive collation is in use then the search will be accent-sensitive. Search for changes in salaries with the date containing number 84 in this case, it means changes that took place in :.

SIMILAR TO matches a string against an SQL regular expression pattern. If any operand is NULL , the result is NULL. Otherwise, the result is TRUE or FALSE. The following syntax defines the SQL regular expression format. It is a complete and correct top-down definition.

Feel free to skip it and read the next section, Building Regular Expressions , which uses a bottom-up approach, aimed at the rest of us. Within regular expressions, most characters represent themselves. The only exceptions are the special characters below:. A regular expression that contains no special or escape characters matches only strings that are identical to itself subject to the collation in use.

A bunch of characters enclosed in brackets define a character class. A character in the string matches a class in the pattern if the character is a member of the class:.

Within a class definition, two characters connected by a hyphen define a range. A range comprises the two endpoints and all the characters that lie between them in the active collation. Ranges can be placed anywhere in the class definition without special delimiters to keep them apart from the other elements. Latin letters a.. z and A.. With an accent-insensitive collation, this class also matches accented forms of these characters.

Uppercase Latin letters A.. Also matches lowercase with case-insensitive collation and accented forms with accent-insensitive collation. Lowercase Latin letters a..

Also matches uppercase with case-insensitive collation and accented forms with accent-insensitive collation. Matches horizontal tab ASCII 9 , linefeed ASCII 10 , vertical tab ASCII 11 , formfeed ASCII 12 , carriage return ASCII 13 and space ASCII Including a predefined class has the same effect as including all its members.

Predefined classes are only allowed within class definitions. If you need to match against a predefined class and nothing more, place an extra pair of brackets around it. If a class definition starts with a caret, everything that follows is excluded from the class.

All other characters match:. If the caret is not placed at the start of the sequence, the class contains everything before the caret, except for the elements that also occur after the caret:. If the braces contain two numbers separated by a comma, the second number not smaller than the first, then the item must be repeated at least the first number and at most the second number of times in order to match:.

A match is made when the argument string matches at least one of the terms:. A subexpression is a regular expression in its own right. It can contain all the elements allowed in a regular expression, and can also have quantifiers added to it. In order to match against a character that is special in regular expressions, that character has to be escaped. There is no default escape character; rather, the user specifies one when needed:. Two operands are considered DISTINCT if they have a different value or if one of them is NULL and the other non-null.

They are NOT DISTINCT if they have the same value or if both of them are NULL. Since NULL is not a value, these operators are not comparison operators. The IS [NOT] NULL predicate tests the assertion that the expression on the left side has a value IS NOT NULL or has no value IS NULL. In Firebird 3.

This group of predicates includes those that use subqueries to submit values for all kinds of assertions in search conditions. Existential predicates are so called because they use various methods to test for the existence or non-existence of some assertion, returning TRUE if the existence or non-existence is confirmed or FALSE otherwise. The EXISTS predicate uses a subquery expression as its argument.

It returns TRUE if the subquery result would contain at least one row; otherwise it returns FALSE. NOT EXISTS returns FALSE if the subquery result would contain at least one row; it returns TRUE otherwise. For now, we'll have to content ourselves with poring over these kinds of corporate submissions for more interesting tidbits like this one.

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The GDM used in conjunction with the TGA allows for automated switching between the gas ports, as well as software-controlled blending of binary mixtures of gases. The added capability to perform controlled blending of binary gas mixtures allows for TGA experiments to be carried out in an atmosphere where the concentration of gases may be in a fixed ratio, stepped incrementally or ramped at a controlled rate.

This accessory can be used to study sorption of gasses onto a material at atmospheric pressure, Redox reactions, and thermal stability of materials in a controlled atmosphere. TGA is used to determine sample composition by measuring the weight of each component as it volatilizes or decomposes under controlled conditions of temperature, time, and atmosphere. This figure shows quantitative differences in type, amount, and decomposition mechanism of the main polymers in three paint samples.

More detailed examination of the profiles below °C may reveal further information on the amount and possible nature of the carrier solvent aqueous or oil used in each paint.

Verification of Thermal Events. TGA is very useful in conjunction with other thermal analysis techniques such as DSC and is often critical to understanding the true nature of thermal events. In this data, a pharmaceutical material undergoes an endothermic transition above °C which was previously thought to be melting. TGA analysis demonstrates considerable weight loss below °C, which suggests that the endotherm is actually decomposition.

DSC analysis at multiple rates exposes rate-dependence of this transition which confirms decomposition. Volatiles Analysis. TGA determinations of absorbed, bound, or occluded moisture, and organic volatiles are important analyses for product performance and environmental acceptance. Analysis of an organic salt hydrate in nitrogen atmosphere shows a bound-water content of 9. These losses are likely due to adsorbed moisture at the salt surface or held to it by weak attractive forces.

TGA is a useful technique for determining the absolute and relative thermal stability of pharmaceutical compounds, as well as the moisture content.

The material is relatively stable up to °C, after which a large, multi-step weight loss is indicative of thermal decomposition. TGA-FTIR: Phenolic Resin Decomposition. This figure contains the TGA-FTIR results for the thermal decomposition of a phenolic resin adhesive. A Gram-Schmidt reconstruction of the time-resolved FTIR spectra is compared to the weight loss signal as a function of time and temperature. The inset image contains the FTIR spectrum of the offgas composition at The FTIR spectrum corresponding to this temperature indicates that the offgas products are primarily composed of phenols, including bisphenol A, which is included as a comparison spectrum.

This level of chemical specificity is useful in comparing similar products, quality control, and fingerprint analysis. TGA Mass Spec Application - Decomposition of An Engineered Plastic. Poly phenylene oxide , or PPO, is an engineering thermoplastic with desirable high-performance specifications for heat resistance, dimensional stability and cost. With a glass transition temperature as high as °C, the injection molding or extrusion processing temperature of PPO would need to be high, and as a result the process can be costly.

Quite commonly, PPO is blended with other polymers such as polystyrene HIPS to aid processing and ductility. In this example, neat PPO is heated to decomposition in an inert nitrogen atmosphere.

The TGA-MS hyphenated technique allows for the detection and identification of the resultant decomposition products. The data is displayed as an overlay of ion current and weight loss with respect to temperature. TGA shows a monotonic weight loss step; however, the mass spectroscopy data presents the detection of several decomposition entities that range in mass to charge ratios of 65 to amu which is the molecular ion of the repeating unit.

Proposed decomposition products based on the structure of the polyether are shown. TGA GDM Application - REDOX Reaction of Copper Oxalate. Copper oxalate CuC 2 O 4 is a salt that decomposes to elemental copper upon heating in an inert atmosphere. It is often used to measure the inertness of the TGA atmosphere, as the high surface area copper is readily oxidized at high temperatures. In this example a REDOX experiment was accomplished using the Blending GDM and the Discovery TGA.

After decomposition of the oxalate, oxygen was introduced into the TGA sample chamber resulting in the formation of copper II oxide; subsequent reduction of the copper oxide was achieved through the introduction of small amounts of hydrogen gas.

Forming gas a H 2 :N 2 mixture is safely used as a hydrogen source in the TGA, as this concentration is below the explosive limit. Discover powerful TRIOS software that delivers exceptional user experience in a combined package for instrument control, data analysis and reporting. New features such as automated calibration routines, multiple calibration sets, real-time test method editing, and inter-laboratory data and test method sharing provide unmatched flexibility , while one-click analysis and custom reporting raise productivity to new levels.

Guided Methods. A Guided Method for Decomposition and Residue provides an easy-to-use interface for new users to obtain desired results with minimal training. Decomposition and Residue. Description The TGA is designed for the researcher that requires the highest level of performance and features in one package.

Please check the errata for any errors or issues reported since publication. See also translations. This document is also available in these non-normative formats: Specification in XML format using HTML5 vocabulary , XML function catalog , and HTML with change markings relative to version 3.

Copyright © W3C ® MIT , ERCIM , Keio , Beihang. W3C liability , trademark and document use rules apply. This document defines constructor functions, operators, and functions on the datatypes defined in [XML Schema Part 2: Datatypes Second Edition] and the datatypes defined in [XQuery and XPath Data Model XDM 3. It also defines functions and operators on nodes and node sequences as defined in the [XQuery and XPath Data Model XDM 3.

These functions and operators are defined for use in [XML Path Language XPath 3. At the time of writing, XSLT 3. It also replicates some of the functions defined herein, notably those concerned with processing of maps, so that these functions are available in XSLT 3. This is the fourth version of the specification of this function library.

The first version was included as an intrinsic part of the [XML Path Language XPath Version 1. The second version was published under the title XQuery 1. The third version, published on 8 April , was the first to carry its own version number, 3. This version 3. A summary of changes since version 3. This section describes the status of this document at the time of its publication. Other documents may supersede this document. This document is governed by the 1 March W3C Process Document.

This is a Recommendation of the W3C. This document was published by the W3C XML Query Working Group and the W3C XSLT Working Group , each of which is part of the XML Activity. This publication differs from its version 3. There are numerous smaller differences as well, all documented in the change log.

This specification is designed to be referenced normatively from other specifications defining a host language for it; it is not intended to be implemented outside a host language.

The implementability of this specification has been tested in the context of its normative inclusion in host languages defined by the XQuery 3. This document incorporates minor changes made against the Proposed Recommendation of 17 January Changes to this document since the Proposed Recommendation are detailed in F.

Please use multiple Bugzilla entries or, if necessary, multiple email messages if you have more than one comment to make. This document has been reviewed by W3C Members, by software developers, and by other W3C groups and interested parties, and is endorsed by the Director as a W3C Recommendation. It is a stable document and may be used as reference material or cited from another document. W3C's role in making the Recommendation is to draw attention to the specification and to promote its widespread deployment.

This enhances the functionality and interoperability of the Web. This document was produced by groups operating under the 5 February W3C Patent Policy. W3C maintains a public list of any patent disclosures W3C XML Query Working Group and a public list of any patent disclosures W3C XSLT Working Group made in connection with the deliverables of each group; these pages also include instructions for disclosing a patent. An individual who has actual knowledge of a patent which the individual believes contains Essential Claim s must disclose the information in accordance with section 6 of the W3C Patent Policy.

The purpose of this document is to catalog the functions and operators required for XPath 3. The exact syntax used to call these functions and operators is specified in [XML Path Language XPath 3. General purpose functions, available for direct use in user-written queries, stylesheets, and XPath expressions, whose arguments and results are values defined by the [XQuery and XPath Data Model XDM 3.

Constructor functions, used for creating instances of a datatype from values of in general a different datatype. These functions are also available for general use; they are named after the datatype that they return, and they always take a single argument.

Functions that specify the semantics of operators defined in [XML Path Language XPath 3. These exist for specification purposes only, and are not intended for direct calling from user-written code. This document defines functions and operations on these datatypes as well as the other types for example, nodes and sequences of nodes defined in Section 2. These functions and operations are available for use in [XML Path Language XPath 3. In particular, they may be referenced in future versions of XSLT and related XML standards.

It introduces a new derived type xs:dateTimeStamp , and it incorporates as built-in types the two types xs:yearMonthDuration and xs:dayTimeDuration which were previously XDM additions to the type system. In addition, XSD 1. Implementations of this specification may support either XSD 1.

References to specific sections of some of the above documents are indicated by cross-document links in this document. Each such link consists of a pointer to a specific section followed a superscript specifying the linked document. The superscripts have the following meanings: 'XQ' [XQuery 3. This recommendation contains a set of function specifications.

It defines conformance at the level of individual functions. An implementation of a function conforms to a function specification in this recommendation if all the following conditions are satisfied:. For all combinations of valid inputs to the function both explicit arguments and implicit context dependencies , the result of the function meets the mandatory requirements of this specification.

For all invalid inputs to the function, the implementation signals in some way appropriate to the calling environment that a dynamic error has occurred. For a sequence of calls within the same · execution scope · , the requirements of this recommendation regarding the · determinism · of results are satisfied see 1. Mechanisms for invoking functions, supplying arguments, initializing the static and dynamic context, receiving results, and handling errors;.

A concrete realization of concepts such as · execution scope · ;. Which versions of other specifications referenced herein for example, XML, XSD, or Unicode are to be used.

Any behavior that is discretionary implementation-defined or implementation-dependent in this specification may be constrained by a host language. Adding such constraints in a host language, however, is discouraged because it makes it difficult to re-use implementations of the function library across host languages. This specification allows flexibility in the choice of versions of specifications on which it depends:. It is · implementation-defined · which version of Unicode is supported, but it is recommended that the most recent version of Unicode be used.

It is · implementation-defined · whether the type system is based on XML Schema 1. It is · implementation-defined · whether definitions that rely on XML for example, the set of valid XML characters should use the definitions in XML 1. The XML Schema 1. Furthermore, XSD 1. In this document, text labeled as an example or as a Note is provided for explanatory purposes and is not normative.

The functions and operators defined in this document are contained in one of several namespaces see [Namespaces in XML] and referenced using an xs:QName. This document uses conventional prefixes to refer to these namespaces. User-written applications can choose a different prefix to refer to the namespace, so long as it is bound to the correct URI. The host language may also define a default namespace for function calls, in which case function names in that namespace need not be prefixed at all.

The section 18 Constructor functions defines constructor functions for the built-in datatypes defined in [XML Schema Part 2: Datatypes Second Edition] and in Section 2. The namespace prefix used in this document for most functions that are available to users is fn. This namespace is used for some mathematical functions. The namespace prefix used in this document for these functions is math. These functions are available to users in exactly the same way as those in the fn namespace.

This namespace is used for some functions that manipulate maps see The namespace prefix used in this document for these functions is map. The namespace prefix used in this document for these functions is array. This namespace prefix is not predeclared and its use in this document is not normative.

There are no functions in this namespace: it is used for serialization parameters, as described in [XSLT and XQuery Serialization 3. Functions defined with the op prefix are described here to underpin the definitions of the operators in [XML Path Language XPath 3. These functions are not available directly to users, and there is no requirement that implementations should actually provide these functions. For this reason, no namespace is associated with the op prefix.

The above namespace URIs are not expected to change from one version of this document to another. The contents of these namespaces may be extended to allow additional functions and errors, and serialization parameters to be defined. A function is uniquely defined by its name and arity number of arguments ; it is therefore not possible to have two different functions that have the same name and arity, but different types in their signature.

That is, function overloading in this sense of the term is not permitted. Consequently, functions such as fn:string which accept arguments of many different types have a signature that defines a very general argument type, in this case item? which accepts any single item; supplying an inappropriate item such as a function item causes a dynamic error.

Some functions on numeric types include the type xs:numeric in their signature as an argument or result type. In this version of the specification, xs:numeric has been redefined as a built-in union type representing the union of xs:decimal , xs:float , xs:double and thus automatically accepting types derived from these, including xs:integer.

It is possible for two functions to have the same name provided they have different arity number of arguments. For the functions defined in this specification, where two functions have the same name and different arity, they also have closely related behavior, so they are defined in the same section of this document. Each function or group of functions having the same name is defined in this specification using a standard proforma.

The function name is a QName as defined in [XML Schema Part 2: Datatypes Second Edition] and must adhere to its syntactic conventions. Following the precedent set by [XML Path Language XPath Version 1.

When the IN predicate is used in the search conditions of DML queries, the Firebird optimizer can use an index on the searched column, if a suitable one exists. Certain operations such as taking the square root of a negative number are defined in IEEE to signal the invalid operation exception and return a quiet NaN. You should enable local link bias if you want to conserve VCP bandwidth by always forwarding egress unicast traffic on a LAG out of a local link. Such a function is said to be non-deterministic with respect to node identity. If the entered number of characters is less than the declared length, trailing spaces will be added to the field. The local minimum links feature is disabled by default.

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