A Method for Determining the Distribution of Cationic Shrink-resist Resins on Wool*

A method for determining the distribution of cationic shrink-resist resins on wool has been developed. The method is based on a staining technique, using an anionic fluorescent brightening agent (FBA) under specific conditions in which the FBA stains the cationic resin in preference to the wool. When the stained samples are observed under ultraviolet radiation by means of the optical microscope, the areas on the wool fibres where resin is located fluoresce, whereas areas free from resin appear dark. The technique is simple and rapid, and enables the regularity of deposition of cationic resins on wool to be followed when the various parameters which play a role in the pretreatment of the fibre and the application of resins are changed. Regularity of resin deposition is important in the achievement of high levels of shrink-resistance in treated fabrics.     

Surface active molecules: preparation and properties of long chain nα-acyl-l-α-amino-ω-guanidine alkyl acid derivatives

A new route for the synthesis of long chain N ^α-acyl- l -α-amino-ω-guamdine alkyl acid derivatives, with cationic or amphoteric character has been established. The general formula of these compounds is shown below.
A physico-chemical and antimicrobial study of these products as a function of the alkyl ester or sodium salt (R), the straight chain length of the fatty acid residue ( x ) and the number of carbons between the ω-guanidine and ω -carboxyl group ( n ) has been investigated.
The water solubility, surface tension, critical micelle concentration (c.m.c.) and minimum inhibitory concentration (MIC) against Gram-positive and Gram-negative bacteria (including Pseudomonas) has been determined.
Dicyclohexylcarbodiimide has been used to condense fatty acids and α -amino-ω-guanidine alkyl acids. In these conditions protection of the ω-guanidine group is not necessary. The main characteristic of this synthetic procedure is the use of very mild experimental conditions (temperature, pH) to form the amide linkage which leads to pure optical compounds in high yield in the absence of electrolytes.
The results show that some structural modifications, particularly the protection of the carboxyl group, promote variations of the surfactant and antimicrobial properties. Only those molecules with the blocked carboxyl group (cationic molecules, where R = Me, Et or Pr) showed a good surfactant and antimicrobial activity. When the carboxyl group was unprotected (amphoteric molecules, where R = Na⁺) the resulting compounds were inactive.     

ESTIMATE OF THE SHELF-LIFE OF BEEF UNDER VACUUM PACKAGING BY OBJECTIVE AND SUBJECTIVE MEASUREMENTS

Abstract This work was carried out in order to establish variables which would be useful to estimate the shelf-life of vacuum packaged beef from the Pirenaica breed. This breed is the main source of beef meat in the Spanish West Pyrenees. Two different fresh beef cuts (rib and chuck) samples were evaluated for total fatty acid composition, pH, lipid oxidation (TBA values), total bacterial counts (APC), Enterobacteriaceae counts and by sensory evaluation after 15 and 30 day under vacuum and then after 3 days of display. The variables that contributed to separating the storage periods determining the shelf-life of vacuum packaged beef were TBA, APC, Enterobacteriaceae counts and the sensory variables of color, odor and overall appearance.     

SUBJECTIVE CONSTRUCTIONS OF NEIGHBORHOOD BOUNDARIES: LESSONS FROM A QUALITATIVE STUDY OF FOUR NEIGHBORHOODS

ABSTRACT: This article explores the boundaries of neighborhoods as subjectively constructed by 37 adolescents and 33 parents across four census‐defined block groups in a Western city. We examine the degree of consensus among participants on the spatial boundaries of their neighborhoods, the stability of participants' subjectively constructed neighborhood definitions, and the overlap between subjectively constructed definitions and census block group and tract definitions. Through an analysis of qualitative interviews, we isolate four factors that appear to influence how participants define their neighborhood boundaries: physical and institutional characteristics of the neighborhood, its class, race, and ethnic composition, perceived criminal threats from within and outside the neighborhood, and symbolic neighborhood identities. These factors can operate to facilitate or compromise consensus and stability about neighborhood boundaries and identity. The study findings are exploratory but suggest several avenues for further investigation into how parents and adolescents construct neighborhood boundaries and the possible influences that subjective neighborhood definitions have on families.     

响应曲面法优化磷脂酶Lecitase Ultra用于茶油脱胶工艺的研究

本研究在单因素试验的基础上,利用Box．Benhnken的中心组合试验设计及响应面分析法优化磷脂酶LeeitaseUltra对茶油脱胶的工艺,建立反应时间、反应温度、酶用量与磷脂脱除率之间的数学模型,确立酶法对茶油脱胶的最佳工艺条件,即反应时间4．3h、反应温度47℃、酶用量44mg／kg。在此最佳工艺条件下,茶油脱胶率达89．41％（n=3）。     

CLOSING AND OPENING SCHOOLS: THE ASSOCIATION BETWEEN NEIGHBORHOOD CHARACTERISTICS AND THE LOCATION OF NEW EDUCATIONAL OPPORTUNITIES IN A LARGE URBAN DISTRICT

ABSTRACT: New charter schools can potentially provide disenfranchised students with enhanced academic opportunities while simultaneously serving as neighborhood anchors that reinforce neighborhood socioeconomic growth. However, for both of these arguments to be true, charter schools would have to replace low‐performing public schools in currently disadvantaged, but revitalizing, neighborhoods. Using data from the Chicago Public Schools, the Common Core, and the Census, we examine the neighborhood and school‐level factors that account for where elementary schools closed and opened in Chicago during the late 1990s and 2000s. We find that schools in disadvantaged neighborhoods were more likely to close, but only because these were also underperforming and under‐enrolled schools. After controlling for educational demand, new schools were more likely to open in neighborhoods that showed signs of socioeconomic revitalization and declining proportions of white residents.     

CONSTANT STRAIN RATE COMPRESSION OF BIOPOLYMER GELS

Usually, uniaxial compression of food materials is performed at constant speed, which causes an increase of the true strain rate during experiments. By using a method described previously (Jaros and Rohm 1994) highly elastic biopolymer gels were compressed at standard conditions and with decreasing crosshead speed in order to maintain constant strain rate conditions during test. In the case of gels showing failure at a Hencky deformation of > 0.5-0.6, significantly lower values for apparent fracture strain were found in constant strain rate compression. Differences in stress at apparent fracture showed good agreement with respect to this critical value. Implications and consequences on interrelation between sensory and instrumental measurements as well as on relationships between rheological and fracture properties are discussed.     

ADAPTATION OR EXTINCTION? COMMUNITY DEVELOPMENT LOAN FUNDS AT A CROSSROADS

ABSTRACT: This article examines community development loan funds (CDLFs), a type of community development financial institution that provides financing and technical assistance for businesses; for‐profit and nonprofit real estate and housing developers; nonprofit organizations looking for facility or operating capital; and low‐income individuals looking for financing to purchase or rehabilitate their homes. Like many nonprofits and social enterprises, CDLFs have experienced a worsening political and economic environment since 2000, leaving many of them struggling to stay alive as the subsidized capital necessary to fund their operations largely has evaporated. The article reviews CDLF origins, structures, and current activities; discusses the field's historic sources of subsidized capital and why they have shrunk; reviews potential new sources of capital and the organizational ways that CDLFs are responding to their changed environment; and makes recommendations for CDLFs, funders, and policy makers. It is based on organizational‐level data from annual surveys of CDLFs conducted by the CDFI Data Project and the Opportunity Finance Network; on two dozen interviews with CDLF, foundation and bank officers and staff and policy makers involved with the field; on documents from individual CDLF institutions; and on contemporary press accounts.     

Surimi-Based Imitation Crab Characteristics Affected by Heating Method and End Point Temperature

Sensory panel scores and Instron compression tests indicated baked and microwaved imitation crab legs were softer (P < 0.05) than unheated controls. Sensory scores further indicated that baked samples were softer (P < 0.05) and less chewy than microwaved samples. End point temperature to which samples were heated (71°C and 93°C) had no effect on results. No differences in moisture content were found among samples, but heated samples were lower (P < 0.05) in expressible moisture than unheated controls. Heating may have caused free water to rebind with starches in the product, thus decreasing expressible moisture, which contributed to decreases in firmness and chewiness.