bluuebunny/crossref_metadata_2025 huggingface dataset:
Hyaluronan Hydrogel/Calcium Phosphates Composites for Medical Application
Authors: Sokolova Marina , Locs Janis , Loca Dagnija
Published: December 2016

The combination of calcium phosphate compounds and hyaluronan is expected to have advantages of both materials to be used as optimal scaffold for bone tissue engineering. It possesses the fundamental necessary characteristics such as bioactivity, biomechanical similarity, processability, and biodegradability. Preparation technology and properties of hyaluronan acid and calcium phosphate composites (HA/CaP) are described in the current study, and for the first time composites with high, up to 0.43 HA/CaP mass ratio are synthesized using chemical cross-linking method.HA/CaP hydrogels were prepared using fixed cross-linker amount at different HA concentrations. Swelling properties of prepared HA/CaP hydrogels were investigated as function of the HA content in composite. The swelling properties of hydrogels were studied in phosphate-buffered saline (PBS) at pH 7.4. It was observed that HA reinforcement with CaP particles increases hydrogel stability, and prepared HA/CaP hydrogels maintained their integrity up to 4 weeks.
Synthesis of Fe-ZrO2 Composite Powders by Thermochemical Method
Authors: Bobrynina Elizaveta , Alali Alkhalaf Ahmad , Shamshurin Aleksey , Tolochko Oleg , Mikhailov Veselin
Published: December 2016

Nanostructured Fe–ZrO2 composite powders with homogeneous distribution of zirconia were synthesized by thermochemical process. The synthesis procedures are (1) preparation of precursor powder by spray-drying of solution made from water-soluble iron and zirconium nitrates, (2) air heat treatments to evaporate volatile components in the precursor powder and synthesis of nanostructured Fe2O3 +ZrO2, and (3) Fe2O3 reduction by hydrogen into pure Fe. In order to find phase containing Zr the powder was treated with 15% hydrochloric acid to dissolve iron particles. The size of the particles is less than 50 nm. Fe–ZrO2 composite powders can be used as filler for cored welding wire. Shown that particles zirconium oxide well affect the final structure of the weld.
Synthesis of Eu2+ and Dy3+ Doped Strontium Aluminates and their Properties
Authors: Rozenberga-Voska Laura , Grabis Jānis , Zolotarjovs Aleksejs
Published: December 2016

Strontium aluminate phosphors were synthesized by the solution combustion method using citric acid, urea or glycine as reducing agent and europium and dysprosium as dopants. The content of both dopants was in the range of 1 – 2 mol%. Dependence of phase composition, crystallite size and specific surface area on calcinations temperature, used reducing agents and dopants were determined. Luminescent properties of the calcinated at 1300 °C powders contained SrAl2O4 (90 %) and Sr4Al24O25 (10%) phases with crystallite size of 80 nm were determined.
Hemp Fibers Waste and Linear Low Density Polyethylene Composite Properties
Authors: Zelca Zane , Kukle Silvija , Kajaks Janis , Geikina-Geimana Marija
Published: December 2016

Influence of the composite preparing technology and filler type (hemp waste and hemp fibres) on the performance characteristics (melt flow index and water resistance) of the composites based on a linear low density polyethylene (LLDPE) was investigated. The best melt flow index (MFI) results were achieved when as composites preparing method extrusion and two rolls mill with lubricant additive combination were used. It is established that usage of extrusion mixing method of the hemp fibers containing LLDPE composites significantly affects materials melts fluidity evaluated by values of MFI and quality of extruded profile. The lowest fluidity was observed for composite with hemp waste prepared by two rolls mill processing method. The best water resistance was observed for composites with lubricant and for their preparing two rolls mill and extrusion processing methods combination was used.
Stability of Suspensions and Emulsions Containing Illitic Clays
Authors: Jurgelane Inga , Stunda-Zujeva Agnese , Berzina-Cimdina Liga
Published: December 2016

There are a lot of studies about colloidal stability of suspensions and emulsions containing clay minerals, but only few about illite containing clays. Due to increasing demand for eco cosmetics, research about the possibility to use natural colloidal particles (clay minerals) as stabilizers also increases. In this study illitic clays were used to investigate the stability of glycerol containing suspensions and safflower oil-in-water emulsions. Three types of clay samples were used – chemically untreated, after removal of carbonates and iron compounds. Viscosity and zeta potential of glycerol suspensions was determined. Samples with the highest viscosity were also the most stable. The removal of iron compounds significantly decreased the viscosity of suspensions and increased the zeta potential
PC/ABS Nanocomposites with Layered Silicates Obtaining, Structure and Properties
Authors: Saldābola Rūta , Merijs Meri Remo , Zicans Janis , Ivanova Tatjana , Berzina Rita
Published: December 2016

Due it increasing use in electronics, polymers, mainly acrylonitrile-butadiene-styrene (ABS) and its blend with polycarbonate (PC), are making considerable part of electronic waste. It has been proven that halogenated flame retardants used in polymers for electronics are toxic to environment and human health. Aim of the research is to evaluate the effects of nanostructured montmorillonite clay (D43B) addition on the mechanical and thermal characteristics of PC, ABS and its binary blends. The effect of substitution of virgin polymers in the blend with recycled ones has been also investigated. It has been determined that as far as the recycled polymer content in the composites does not exceed 10wt.%, tensile and thermal properties of the systems are not considerably affected. Addition of D43B up to 1,0-1,5wt.% contributes to the increment of mechanical stiffness, strength and thermal stability of the composites.
Microwave Synthesis and Properties of Thin Layer Pt Modified TiO2 Nanofibers Coating
Authors: Drunka Reinis , Grabis Jānis , Jankovica Dzidra , Krūmiņa Aija
Published: December 2016

In the present work formation of macro-size TiO2 nanofiber layers in microwave synthesis were studied. Anatase nanopowder and 10M KOH solution were used as raw materials. Microwave assisted synthesis method permitted to obtain TiO2 nanofibres containing individual nanowires with a diameter of 5nm and a specific surface area up to 129m2/g. Macro size layer of TiO2 nanofibers was obtained on the surface of microwave vessel. Total surface area covered with TiO2 was about 390cm2. Modification with platinum allows to increase photocatalytical activity of TiO2 macro size fiber layer up to 94.4% in UV irradiation and up to 11.6% under visible light irradiation.
Structure and Hydrophobicity of Fe2O3-TiO2 Coatings
Authors: Zukuls Anzelms , Mezinskis Gundars
Published: December 2016

Fe2O3–TiO2 coatings were successfully prepared on glass slide substrates using sol–gel method for wettability applications. The microstructure and surface properties of the coatings were extensively characterized by using X-ray diffractometry (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). Different solutions were prepared by adding distilled water to sol solution. Glass substrates were coated by solutions of Ti-alkoxide, Fe-chloride hexahydrate, ethylene glycol, acetic acid, isopropanol and glycerol. The obtained gel films were dried at room temperature for 15 min in air. The oxide thin films were annealed at 500 ºC for 1h. The influence of distilled water concentration and withdraw speed on contact angle of the films was established. In addition, XRD results revealed that Fe2O3–TiO2 films composed of anatase, rutile, brookite and hematite phases. The purpose of this contribution was the investigation of different preparation parameters during the synthesis of iron oxide rich Fe2O3–TiO2 thin hydrophobic films on glass substrate. SEM and AFM observations revealed leaf-like structure formation on a coating surface.
Evaluation of Residual Stresses in PVD Coatings by Means of the Curvature Method of Plate
Authors: Lille Harri , Ryabchikov Alexander , Adoberg Eron , Kurissoo Liisa , Peetsalu Priidu , Lind Liina
Published: December 2016

Physical Vapor Deposition (PVD) coatings are primarily designed for metal cutting tools operating in extreme machining and blanking conditions. Residual stresses arising during coating deposition exert an important effect on the service life of the coating through influencing mechanical and tribological properties and adhesion. To determine macroscopic residual stresses, the conventional curvature method was used. As an application, residual stresses in four aluminum based PVD hard coatings, i.e. AlTiN, AlTiSiN, AlCrN, and AlCrSiN, were investigated in the presence of the Ti adhesion layer. Nickel steel plates and steel plates were used as the substrate. Residual stresses were compressive and high (3.0-7.5 GPa) in all coatings. Compressive stresses in coatings are desirable in cohesive tool damage as they strengthen the coating. The values of residual stresses were not significantly dependent on the angle of plate placement (parallel (0°), inclined (45°) and perpendicular (90°)) in relation to the PVD cathode in the deposition chamber. The magnitude of residual stresses is influenced by intrinsic strain at layer growth rather than by thermal stress.
Tribological Behavior at Dry Sliding by Electric Current of Cu-Cr-S Alloy after Equal Channel Angular Pressing
Authors: Kommel Lembit
Published: December 2016

The wear tests of ultrafine-grained Cu-0.68Cr-0.02S energy alloy after equal channel angular pressing followed heat treatment were carried out in alloy-graphite sliding pair system without lubricant at different contact electrical current density. The sutable microstructure, mechanical properties and electrical conductivity of severely deformed alloy have been formed on the samples with different levels of parameters of thermomechanical processing. The microstructure and wear surfaces of the samples have been studied using optical microscope and field emission scanning electron microscope equipped with energy dispersive spectrometer. The results illustrated that the mass loss at wear, wear rate and wear mechanism depend on microstructure, hardness and electrical conductivity of test materials as well as normal pressure stress and electrical current density on the contact surface. The mechanical and physical properties of alloy, testing parameters and their influence on the wear rate as well as wear mechanism are analyzed.
Synthesis of NiO Nanoparticles by Microwave Assisted and Molten Salts Methods
Authors: Grabis Jānis , Heidemane Gundega , Krūmiņa Aija
Published: December 2016

Nickel oxide nanoparticles were prepared via molten salts and microwave assisted synthesis from nickel nitrate and the parameters of obtained nanopowders were compared. NiO nanoparticles with crystallite size in the range of 6-8 nm have been prepared by combining microwave assisted treatment of Ni (NO3)2 and urea solution with calcination at 300-320 °C. Molten salts (NaNO2-NaCl) ensured direct formation of NiO from Ni (NO3)2.6H2O and salts mixture at 350 °C but crystallite size of the particles reached 51-69 nm.
Fungal Degradation of Wood Plastic Composites Made with Thermally Modified Wood Residues
Authors: Kuka Edgars , Cirule Dace , Kajaks Janis , Janberga Anna , Andersone Ingeborga , Andersons Bruno
Published: December 2016

Wood plastic composites (WPC) are mainly used as an outdoor material, so durability against fungal decay is one of the factors that should be analyzed and if necessary improved. WPC are susceptible to biodegradation, although these materials have limited water absorption because of the wood fiber encapsulation in polymer matrix. In the study two different water pretreatment methods (short-term and long-term) were used to ensure appropriate water content for fungal growth. Also in the paper thermally modified wood (different regimes) fiber influence on WPC fungal resistance is investigated. The results showed that long-term water pretreated WPC specimens had more suitable conditions for fungal degradation that led to higher weight loss. The results which were related to thermally modified wood fibers showed, that WPC with thermally modified wood fibers had improved resistance against fungi. Thermal modification regimes had an effect on WPC durability as well.
Grindability of CFBC Fly Ash and High Temperature Fly Ash
Authors: Šulc Rostislav , Vašák Martin , Poláček Jaromír
Published: December 2016

This article presents the results of fly ash from Circulating fluidized Bed Combustion (CFBC) and high temperature fly ash (defined in EN 450-1) with modified physical parameters by grinding. For this treatment was used the mechanical mill. In this case were used two fly ashes. The first sample was from Tisová power plant (CFBC fly ash) and the second one from Počerady power plant (high temperature fly ash). The modified samples were tested for the effect of grinding time on its grindability and granulometry. For testing of samples was used laser diffraction with particle size analyzer and the grindability was determined. The reason for this step was found more stable and better material which achieves better physical and mechanical properties. The first step is mechanical treatment of fly ash’s granule.
The Speed of the Crystalline Admixture’s Waterproofing Effect in Concrete
Authors: Pazderka Jiří , Hájková Eva
Published: December 2016

There have been many experimental measurements of the waterproofing ability and durability of concrete with a crystalline admixture but there are uncertainties about the speed of the waterproofing effect caused by the crystalline admixture. The paper describes water pressure test carried out in different time intervals during the initial phase of cement hydration. The test results have shown that the full waterproofing effect of concrete with a crystalline admixture was available approximately on the 12th day after the concrete creation.
Long-Term Development of Strength of Cement Paste with Fly Ash
Authors: Zobal Ondřej , Padevět Pavel
Published: December 2016

The paper deals with the long-term development of strength of cement paste with fly ash. If the fly ash replaces the clinker in the cement or concrete mixture, the properties of the fresh and hardened material are affected. The slower increase in the strength of concrete is one of the biggest negative impacts. However, there are applications where it does not matter - e.g. massive concrete structure. It is important due to the ever increasing requirement from society for saving material and energy and durability of structures monitoring long-term behavior of such modified material. Three different mixtures were made for this experiment - cement paste without fly ash and cement paste with replacement of 40 and 50% of cement by fly ash. The evaluation of the measurement of compressive and tensile strength after 28, 90, 180 days and 5 years is presented in this paper.
The Carbonation Depth of Fine Recycled Aggregate Concrete
Authors: Šefflová Magdaléna , Pavlů Tereza
Published: December 2016

This paper is focused on carbonation resistance of fine recycled aggregate (FRA) concrete. Durability of FRA concrete is connected with uncertainties and doubts. One of the most unknown aspects of FRA cocnrete is carbonation resistance. This paper presents results of carbonation depth of FRA concrete. The FRA was originated from crushed construction and demolition (C&D) waste. There were prepared a total four concrete mixture. The first mixture was reference, did not include the FRA. In other concrete mixtures, natural sand was replaced by the FRA in various replacement ratios, specifically 10%, 20% and 30%. All prepared concrete mixtures were designated with the same parameters for clear comparison. From the test results it is possible to say that the use of the FRA as partial replacement of natural sand in concrete influences carbonation resistance of concrete. The carbonation depth was higher for concrete samples with the use of FRA. However it is possible to say that according to the carbonation resistance, the FRA concrete is possible to be used in the same applications as conventional concrete but it is necessary to verify this results.
Ultrasonic Pulse Method - Influence of Internal Compressive Stress on Results of Testing Calcium Silicate Bricks
Authors: Brožovský Jiří
Published: December 2016

Measuring with ultrasonic pulse method is influenced by various factors, like loading in particular inner tension when material built in a construction is tested. The paper researches influence of inner tension (load) on testing of calcium silicate bricks with ultrasonic pulse method. Calcium silicate bricks were loaded with force corresponding to 0 % (unloaded test specimens), 10 %, 20 %, 50 %, 60 % of ultimate compressive strength with various content of humidity (dried samples, w=2 %, w=8 % and samples saturated with water). It was found that ultrasonic pulse velocity is not considerably influenced at load of 10% and 20% of ultimate strength of bricks. However, ultrasonic pulse velocity considerably decreases after loading at 50% and 60% of ultimate compressive strength. Most of theoretical assumptions concerning mentioned concrete stated in technical literature were confirmed, however, particular values were different because of differences between concrete and calcium silicate bricks.
Long-Term Mechanical Properties of Fiber Reinforced Polymer Bars Exposed to Alkali Environment: Experimental Investigation
Authors: Girgle Frantisek , Bodnárová Lenka , Matusikova Anna , Kostiha Vojtech , Prokeš Jan , Januš Ondřej
Published: December 2016

This paper deals with actual issues concerning the design and the utilization of modern composite reinforcement (FRP) in concrete structures. These advanced composite materials are, especially if the whole life cycle of the structure is considered, gradually becoming a convenient alternative to ordinary steel reinforcement. The structure reinforced with FRP reinforcement (as well as the structure reinforced with steel reinforcement) has to be designed with regard to sufficient endurance, serviceability and durability. The long-term material properties of FRP reinforcement embedded in concrete, which are influenced by temperature, load magnitude and ambient environment, must be considered during design of the structure. A high alkali environment of concrete with pH higher than 12.0 acts mainly on glass fibres which degrade and their mechanical properties are reduced consequently. The used matrix creates a barrier which insulates the bearing fibres against alkali ions attack. The main objective of the paper is therefore to describe behaviour of composite as a whole. The experimental approach and results which were reached during the tests are also presented. An effort was to specify the impact of alkali environment on the long-time properties of developed reinforcement which could be used in durable concrete structures.
Options of UHPC in the Czech Republic
Authors: Křížová Klára , Hela Rudolf
Published: December 2016

This contribution describes the possibilities of UHPC concrete production. To begin with, the fundamental characteristic of this concrete, its development and composition are provided. An essential element for achieving the extraordinary properties of UHPC concrete is its composition. The experimental part describes the UHPC design, test examples and the testing of certain compressive strengths and tensile bending strength after 1 and 28 days. Simultaneously, basic UHPC buildings in the Czech Republic are mentioned.
Bond Characteristics of TRC Slabs Cured in Autoclave
Authors: Holčapek Ondřej
Published: December 2016

Textile reinforced concrete (TRC) found its application in real practice and several producers and companies included TRC ́s elements into their production program. The most popular and widespread are slim façade panels with high aesthetic quality and excellent durability. Curing conditions influence the final properties, which is important especially in precast production where special devices can be used. This paper deals with experimental investigation of bond characteristics of slabs made from TRC hydrothermally cured in autoclave device and reference slabs cured in laboratory conditions for 28 days. Dimension of TRC slabs was 230 x 100 x 20 mm. Compressive strength 100 MPa characterizes used cement matrix (laboratory cured after 28 days). Basalt and AR-glass fabrics with different properties were used as reinforcement. Three-points bending test with clear span of supports 200 mm evaluated maximum bond capacity and load-deflection diagrams described character of failure and ductility.
Dosage of Metakaolin in High Performance Concrete
Authors: Ženíšek Michal , Vlach Tomáš , Laiblová Lenka
Published: December 2016

This article deals with optimal dosage of metakaolin as addition in high performance concrete. The main criteria for assessing the optimal dosage of metakaolin was compressive strength, rheological behaviour and economic benefits. Metakaolin was added to the mixture of high performance concrete in the range from 0 to 25% weight of cement. The comparison of metakaolin and microsilica, which is often used by concrete producers due to its excellent properties, is also performed in this article. The experiments showed that using metakaolin as addition in high performance concrete affects the compressive strength and rheological behaviour positively. While the compressive strength increases especially at lower doses of metakaolin and at higher doses remained unchanged, changes in rheological behaviour were most obvious at the higher doses. From this point of view, it is possible to recommend a higher dose of metakaolin.
Influence of the Aggregate Type on the Properties of Dolomitic Lime-Based Mortars
Authors: Vyšvařil Martin , Žižlavský Tomáš , Bayer Patrik
Published: December 2016

Considering the requirement of numerous restoration work on historical buildings with dolomitic lime-based mortars, a research of the applicability and suitability of various types of plasters for repairing the historical plasters have been developed. This work presents the applicability of limestone aggregate and limestone fines to dolomitic lime-based mortars. The role of aggregates on the properties of dolomitic lime mortars was examined by comparing pure quartz sand and limestone aggregate and its quantity in the mortar. Limestone aggregate and limestone fines accelerated the carbonation reaction in the mortars, but the positive impact of limestone aggregates to strength properties of mortars was not observed. Mortars with limestone aggregate showed higher total porosity and water absorption than those with quartz aggregate. Similar results was obtained for mortars with limestone fines. It was found that limestone aggregate and limestone fines, used in this work, is not so suitable and applicable to the dolomitic lime-based mortar as to the aerial lime-based mortars.
Norwood Procedure for Palliation of Hypoplastic Left Heart Syndrome: Right Ventricle to Pulmonary Artery Conduit vs Modified Blalock-Taussig Shunt
Authors: Beke Dorothy M.
Published: December 2016

Patients with hypoplastic left heart syndrome undergo a series of operations to separate the pulmonary and systemic circulations. The first of at least 3 operations occurs in the newborn period, with a stage I palliation. The goal of stage I palliation is to provide pulmonary blood flow and create an unobstructed systemic outflow tract. Advances in surgical techniques and intraoperative and postoperative care have helped decrease morbidity and mortality for patients with hypoplastic left heart syndrome who have the stage I Norwood operation, but the patients continue to be at increased risk for hemodynamic collapse and adverse outcomes. This article discusses risk factors, surgical approach, postoperative nursing and medical management strategies, differences between and outcomes for the Norwood operation with the right ventricle to pulmonary artery conduit and the Norwood operation with a modified Blalock-Taussig shunt.
Adsorptive Behavior of Arsenic(III) Ions from Aqueous Solution onto Forestry and Agricultural Waste Biochar Pyrolyzed at 400°C
Authors: Gunatilake S.K.
Published: December 2016

Sorption capacity of two different biochar (saw dust and rice straw) was evaluated in the recovery of arsenic from aqueous solutions. Biochar from rice straw and saw dust were obtained from pyrolysis of biomass at 400°C. The optimum sorption conditions were studied for different concentrated monometallic system. Sorption studies were performed at different pH, contracting time and different initial metal ion concentration in the batch mode. The optimum pH was 3 for recovery of As(III) and kinetic studies yielded an optimum equilibrium time of 50-60 minutes with an adsorbent dose of 1 g/L and initial concentration ∼20 mg/L for As(III) ions. As(III) ions in aqueous solution were transported to biochar surface through adsorption and intra-particle diffusion process. Experimental data for As(III) ions was fitted a Langmuir model with R2 value for As(III) 0.969, 0.879 for saw dust and rice straw respectively. The Freundlich constant, KF values for removal of As(III) ions by saw dust and rice straw were 0.9127, 0.8951 respectively. The 1/n value for arsenic ions obtained from saw dust and rice straw were 0.209, 028 and indicate the normal sorption of As(III). The values indicated the affinity of the sorbent towards the uptake of As(III) ions were favorable and rice straw and saw dust biomass can be used to remove Arsenic(III) ions from aqueous phase.
External Insights to Boost Internal R&D Efforts of the Fish and Seafood Export Processing Industry in Sri Lanka
Authors: De Silva D.A.M. , Bjorndal Trond
Published: December 2016

This research is focused on the fish and seafood export industry of Sri Lanka, considering its importance to the country’s economy. The objectives of the study are to investigate the nature of open innovation practices among fish and seafood exporters in Sri Lanka and to find out the role of open innovation on product and process development, market identification, market expansion, brand image, quality control, labelling and certification, sales promotion and advertising, and the sustainability of the resource base. The empirical study is based on the data obtained from 26 EU approved fish and seafood processing establishments. A structured questionnaire followed by interviews with CEOs, R&D heads and quality controllers were the principal data collection tools. Hansen and Birkinshaw’s capability measure is used to measure the firm’s level on idea generation, conversion and diffusion. Processing firms were divided into three groups; idea-rich/poor, conversion rich/poor and diffusion rich/poor. Hypothesis testing proved the positive relationship between firm performance and open innovation practices of the firms. Results reveal that firms are idea rich, conversion and diffusion moderate. Moreover, the study has identified open innovation partners, the nature of their support and the open innovation process of the fish and seafood export processors.
Performance of A Sodium Thiocyanate Based Gel Polymer Electrolyte In Redox Capacitors
Authors: Bandaranayake C.M. , Jayathilake Y.M.C.D. , Vidanapathirana K.P. , Perera K.S.
Published: December 2016

Solid state redox capacitors have received a tremendous interest in terms of several characteristics such as their fast energy delivery, short charging time, high power density and extended durability. Due to the absence of a liquid electrolyte, they are free from drawbacks of leakage and unsafe. In this study, preparation and characterization of a redox capacitor consisting with two identical polypyrrole (PPy): dodecylbenzenesulfonate (DBS) electrodes and a gel polymer electrolyte (GPE) based on polyvinylidene fluoride (PVdF), ethylene carbonate (EC), propylene carbonate (PC) and sodium thiocyanate (NaSCN) is reported. The GPE having the composition, 0.4 PVdF: 1 EC: 1 PC: 0.075 NaSCN (by weight) showed the maximum conductivity of 2.25× 10-3 S cm-1. Redox capacitors were characterized using Cyclic Voltammetry, Electrochemical Impedance Spectroscopy and Galvanostatic Charge Discharge test. They exhibited an energy density about 0.25 W h kg-1 and an average power density of 4 kW kg-1.
Fragmentation of maternal, child and HIV services: A missed opportunity to provide comprehensive care
Authors: Haskins Lyn J. , Phakathi Sifiso P. , Grant Merridy , Mntambo Ntokozo , Wilford Aurene , Horwood Christiane M.
Published: December 2016

Background: In South Africa, coverage of services for mothers and babies in the first year of life is suboptimal despite high immunisation coverage over the same time period. Integration of services could improve accessibility of services, uptake of interventions and retention in care.Aim: This study describes provision of services for mothers and babies aged under 1 year.Setting: Primary healthcare clinics in one rural district in KwaZulu-Natal, South Africa.Methods: All healthcare workers on duty and mothers exiting the clinic after attending well-child services were interviewed. Clinics were mapped to show the route through the clinic taken by mother–baby pairs receiving well-child services, where these services were provided and by whom.Results: Twelve clinics were visited; 116 health workers and 211 mothers were interviewed. Most clinics did not provide comprehensive services for mothers and children. Challenges of structural layout and deployment of equipment led to fragmented services provided by several different health workers in different rooms. Well-child services were frequently provided in public areas of the clinic or with other mothers present. In some clinics mothers and babies did not routinely see a professional nurse. In all clinics HIV-positive mothers followed a different route. Enrolled nurses led the provision of well-child services but did not have skills and training to provide comprehensive care.Conclusions: Fragmentation of clinic services created barriers in accessing a comprehensive package of care resulting in missed opportunities to provide services. Greater integration of services alongside immunisation services is needed.
THE EFFECT OF COPPER ON DISTILLED WATER QUALITY FOR USE IN MILK AND WATER LABORATORIES
Authors: Ronald Gene W. , Morris R. L.
Published: December 2016

Levels of copper toxicity have been established in distilled water using the distilled water suitability test. It is shown that levels of copper, toxic by the distilled water suitability test, are not toxic to the test organism, Aerobacter aerogenes, in sterile milk or to the normal bacterial flora of a raw milk sample.

It is the contention of this paper that the distilled water suitability test is an unrealistically severe yardstick of distilled water quality for use in routine milk and water laboratories.
PROTEIN “SOLUBILIZATION” AND CALCIUM AND MAGNESIUM PRECIPITATION BY “CHLORINATED CLEANERS”1
Authors: Wright E. O. , LaGrange W. S. , Dennis Connie , Bird E. W. , Hotchkiss D. H.
Published: December 2016

It has been stated that chlorinated cleansers increase the “protein solubilization” properties of cleanser solutions to which they are added (7). Chlorinated cleansers, however, are alkaline materials which increase the active alkalinity of the solutions to which they are added; this seems to have been overlooked. The study reported here was undertaken to determine whether the added available chlorine or the increase in active alkalinity was responsible for the increase in protein solubilization.

Two chlorine sources were employed: Sodium hypochlorite (Chlorox) and chlorinated TSP. The approximate amounts by which these chlorine sources increased the active alkalinity (as % NaOH) at the 100 ppm and 200 ppm levels were: Chlorox, 0.0091% and 0.0199%, and chlorinated TSP, 0.0425% and 0.0800%.

When the active alkalinity was the same in two solutions , there was no significant difference in the amounts of protein they would dissolve, even though one of the solutions contained available chlorine and the other did not. However, the pairs of solutions containing the same percentage of active alkalinity as the solution containing 200 ppm available chlorine solubilized significantly more protein (p <0.06) than did the pairs which contained the same active alkalinity as the solution containing 100 ppm; this is attributed to the higher active alkalinity of the former. These results were the same whether Chlorox or chlorinated TSP was the chlorine source, whether the direct or indirect method of determining protein solubilization was employed, and in the direct method, whether skim or homogenized milk was the soiling agent. On the basis of these data, the increase in active alkalinity, not the added available chlorine appears responsible for the increase in protein solubilization when a chlorine source is added to an alkaline cleanser.

No calcium remained in any of the spent cleansers from the direct method of evaluating protein solubilization. In general, the amount of magnesium remaining decreased as the active alkalinity of the solution increased. There was no significant difference in magnesium content between the chlorine-containing and chlorine-free solutions having the same active alkalinity. Chlorine sources apparently minimize precipitation of hard water cations onto equipment surfaces.
METHODS FOR THE QUALITATIVE AND QUANTITATIVE DETERMINATION OF AFLATOXINS1
Authors: Marth E. H.
Published: December 2016

Qualitative and quantitative measurements of aflatoxins are most often routinely made by means of thin-layer chromatography. The accuracy of the quantitative determination by this procedure can be improved by substituting a densitometric “reading” of the thin-layer plates for visual examination. Examination of small samples (down to 0.3 mg) can be accomplished by a modified thin-layer chromatography procedure which employs an acetone-water extraction technique. Confirmation of toxicity is most often done with the duckling bioassay although embryonated chicken eggs have been used successfully for this purpose. Other methods which, under certain circumstances, may find application in the measurement of aflatoxins include: paper chromatography, microbiological assay, spectrophotometry, and a tissue culture assay.
THE FATE OF SALMONELLAE IN THE MANUFACTURE OF COTTAGE CHEESE
Authors: McDonough F. E. , Hargrove R. E. , Tittsler R. P.
Published: December 2016

The effects of cooking temperatures ranging from 110 to 130 F on the fate of salmonellae during the manufacture of Cottage cheese were determined. Seven test species noted for heat resistance and occurrence in dairy products were used to inoculate cheese milk. Salmonellae determinations were made on the milk, whey, curd and cheese at varying stages of manufacture. Salmonellae survived at 110 and 115 F in all trials, and at 120 F in 1 of 5 trials. None survived at 125 F. Creamed Cottage cheese was inoculated with salmonellae, stored at 40 F and analyzed periodically. No marked decrease in numbers was observed during storage.
USE OF A MODIFIED MILK QUALITY TEST ON REFRIGERATED MILK AND COMPARISON WITH OTHER MASTITIS TESTS1
Authors: Elliott L. P.
Published: December 2016

The milk quality test (MQT) was found to be inadequately sensitive for testing milk after overnight refrigeration. It was adapted, however, so it could be used on refrigerated milk. It proved to be a fast, simple and accurate indirect test for mastitis that compared quite well with other known mastitis tests.
QUALITY CONTROL PROGRAMS OF MILK MARKETING COOPERATIVES IN THE UNITED STATES1
Authors: Freeman T. R. , Randolph H. E.
Published: December 2016

Replies were received from 63 of 123 cooperatives surveyed. The smallest cooperatives were located in the Western region and the largest in the North Atlantic region. There was no relationship between the size of the organization and the number of fieldmen employed per 100 members or per million pounds of milk produced. Of the 57 cooperatives employing fieldmen, 45 reported that 50% or more of their fieldmen's time was devoted to raw milk quality problems. Opinion was divided about equally as to whether raw milk quality problems should be the responsibility of the cooperative, or jointly of the plant, the cooperative, and the regulatory agency. A great diversity was found in the frequency and method of evaluating raw milk quality by the cooperatives. Eighteen basic types of tests were used, with tests for inhibitors and total bacteria counts being the most popular.
THE INFLUENCE OF VACUUM PASTEURIZATION UPON THE FREEZING POINT AND SPECIFIC GRAVITY OF MILK
Authors: Demott B. J.
Published: December 2016

The freezing point of milk was raised approximately 0.005 C by passing the milk through a two-stage vacuum pasteurization system to a filler. Milk had a warmer freezing point after passing through the first vacuum chamber than before, indicating some condensation of water vapors, and/or removal of CO2 in this chamber. After passing through the second vacuum chamber the milk had about the same freezing point as it did after the first vacuum treatment. The specific gravity was decreased by clarification but was not altered by vacuum treatment. Milks collected over an 18-months' period were found to have an average freezing point 0.0065 C warmer after processing than before processing.
THE USE OF THE 0.01 ML LOOP IN THE PLATE LOOP METHOD FOR MAKING VIABLE COUNTS OF MILK1
Authors: Thompson D. I. , Black L. A.
Published: December 2016

A-plate loop count method for determining viable counts of pasteurized milk products is described. The technique uses a 0.01 ml calibrated platinum alloy loop attached to a continuous pipetting syringe for rinsing the 0.01 ml of sample into a petri dish with 1 ml of sterile buffered dilution water prior to pouring with agar. Results with this method indicate that accuracy within ± 15 percent is attainable on samples of skim, 2 percent, homogenized, whole milk, and half and half. Measurements of chocolate milk were not accurate.
IMPROVED PROCEDURES FOR MEAT SANITATION1
Authors: Bothast R. J. , Ockerman H. W. , Cahill V. R.
Published: December 2016

A procedure is described for securing and maintaining rabbit carcasses at a low bacterial level during storage. The procedure consists of conventional slaughtering and dressing, a 90-sec dip in 90 C (194 F) water, packaging, and sealing in a sterile container in a sterile environment followed by storage at 3 C (37 F). The dip procedure reduced the surface psychrophilic bacterial load and, when combined with refrigerated storage, this treatment eliminated all detectable growth on the carcasses when evaluated by means of tryptone glucose extract agar. Oxidation was increased by this procedure primarily as a result of lingering peracetic acid used in equipment sterilization. Only slight visual and odor deteriorations were observed in the rabbit carcass after 35 days of storage.
DESIGN OF EYEPIECE RETICLES FOR USE IN THE DIRECT MICROSCOPIC SOMATIC CELL COUNT METHOD1
Authors: Schultze W. D.
Published: December 2016

Criteria have been developed for the design of eyepiece reticles to be employed in the Direct Microscopic Somatic Cell Count method. For each of several levels of somatic cell concentration in milk at which regulatory (control might be exercised, we show the range of widths of the milk film strips required to maintain the desired precision of cell count. These widths are related to the actual distances between rulings on the eyepiece reticle for commonly used microscopes. The proper line spacing is determined for reticles to be used at each of certain cell count control levels, and the limitations on compatible microscope optical equipment are specified.
IMPROVING THE BACTERIOLOGICAL QUALITY OF CHICKEN FRYERS1,2
Authors: Keel J. E. , Parmelee C. E.
Published: December 2016

Two commercial fryer processing operations were investigated to determine the bacteriological quality of the fryers during and after evisceration. Alterations of washing, rinsing, and chilling methods were made to reduce bacterial numbers on skin surfaces of fryers. Swab samples were collected from fryer skin surfaces at various points in the processes and from table surfaces. Total plate counts, psychrophile counts, and coliform counts were determined.

Total plate counts provided the greatest amount of useful information. Coliform counts were not suitable indicators of bacteriological conditions in the evisceration process.

The major sources of bacteria on the skin surface of chilled fryers were the skin of freshly picked fryers and contamination added during the transfer of carcasses from the picker to the evisceration line. Evisceration of the fryers did not add significant numbers of bacteria to the skin surface. Bacteria on the skin of freshly picked fryers were firmly affixed to the surface. They could be removed in increased numbers by combining increased volumes of wash water with the scrubbing action of flexible rubber fingers in the washer.
SHORT-TIME MEMBRANE FILTER METHOD FOR ESTIMATION OF NUMBERS OF BACTERIA1
Authors: Frazier W. C. , Gneiser D. F.
Published: December 2016

Directions are given for the 8- to 12-hr membrane filter-colony technique for the estimation of numbers of viable bacteria in rinsings or swabbings from the surfaces of foods or equipment. Tests on 6 species of bacteria often found in foods demonstrated good recovery of organisms from pure cultures or mixtures of 2 or 3 cultures. Tests with dairy rinses and fresh green beans and sweet com gave counts almost as high as by the 48-hr plate, count. Results with frozen or blanched and frozen beans and corn and with chlorinated flume waters were unsatisfactory.
FLOW CHARACTERISTICS IN HOLDING TUBES OF COMMERCIAL EGG PASTEURIZERS
Authors: Kaufman V. F. , Ijichi K. , Putnam G. W.
Published: December 2016

Fluid flow theory, as related to the holding of egg products in continuous pasteurization operation, is discussed. The conditions for laminar, turbulent and transitional types of flow; the specific factors in holding tubes that may cause deviations from the anticipated type of flow; and the effects of the viscosities of egg products are outlined. Retention times for laminar flow and the effects on survival of microorganisms are evaluated.

Determination of minimum holding times in 10 commercial holding tube arrangements with varying egg products were made. All minimum holding times were appreciably less than average holding times but more than would be predicted from simple laminar flow theory. Holding tube efficiencies varied roughly from 60 to 80%. They increased slightly with increased Reynolds numbers over the range of the latter that is found in commercial holding tubes.
CORRELATION OF FOUR MASTITIS DETECTION TESTS WITH RESPECT TO THE LEUCOCYTE COUNT
Authors: Jensen Christen , Beck Lyle D.
Published: December 2016

A descending order of correlation with respect to the Microscopic Leucocyte Count was obtained as follows: Feulgen-DNA > California Mastitis Test > Modified Whiteside Mastitis Test > Strip Tray Test.

The average overall sample per cow and the composite sample correlations were statistically significant at the 1% level of significance, but many individual composite relationships were not significant. The bulk tank correlations, which represent the entire herd, were not significant. Results indicate that intermixing of raw milk from different sources lowered the concentration of reactive nuclear material to such a level that it was not measurable by the mastitis screening tests employed in these trials.
ESTIMATION OF EXTRANEOUS MATTER IN MILK, CREAM, AND BUTTER
Authors: Maloney P. , Armstrong J. G.
Published: December 2016

Methods for the estimation of amounts of extraneous matter (or sediment) in milk, cream, and butter are discussed and methods suitable for use in routine examinations of these products are suggested. Proposed for estimations in milk, is a mixed sample method in whieh a 10 fluid oz sample is filtered through an area of 0.40-inch diameter. A guide having four discs of this diameter with 0.05, 0.15, 0.20, and 0.30 mg of standard sediment is preferred for scoring these test discs. For estimations in cream and butter, samples of 100 ml and 45 g, respectively, are dispersed in hot water (or, for cream, in hot sodium citrate solution) and filtered through an area of 0.25-inch diameter. A guide having discs of this diameter with 0.10, 0.15, 0.25, and 0.35 mg of standard sediment is proposed for scoring cream and butter test discs.
A COMPARISON OF DIRECT PLATING AND ENRICHMENT METHODS FOR DETECTION AND ENUMERATION OF COAGULASE-POSITIVE STAPHYLOCOCCI IN FROZEN FEEDS OF ANIMAL ORIGIN1
Authors: Chou C. C. , Marth E. H.
Published: December 2016

Direct surface plating on five selective and differential agar media and enrichment prior to plating were compared for detection and enumeration of coagulase-positive staphylococci in frozen feeds. The enrichment medium was trypticasc soy broth (TSB) fortified with 8, 10, and 12% sodium chloride. In general, direct plating on mannitol salt (MS) and staphylococcus 110 (S110) agars was accompanied by a higher recovery of coagulase-positive staphylococci than was obtained with tellurite polymyxin egg yolk (TPEY), Vogel-Johnson (VJ), and tellurite glycine (TG) agars. Suspected colonies picked from TPEY agar were most likely, and from TG agar were least likely, to be coagulase-positive staphylococci.

Enrichment for 24 hr in TSB containing 8 or 10% sodium chloride yielded more staphylococci than did direct plating on TPEY or TG agars. Numbers obtained by the two procedures usually were more nearly equal when MS or S110 agars were used for direct plating. Enrichment in TSB containing 12% sodium chloride or incubation of broths for 48 instead of 24 hr, even if they contained 8 or 10% sodium chloride, were detrimental to the recovery of coagulase-positive staphylococci. Of the plating media tested, MS, TG, and VJ agars regularly and uniformly recovered coagulase-positive staphylococci from enrichment broths inoculated with highest dilutions of test samples. In contrast to this, erratic results were obtained when S110 and TPEY agars were used to recover these bacteria from the same broth cultures.

Tests on feed-grade frozen meat by-product revealed the presence of 103 to 104 coagulase-positive staphylococci per gram in two samples and 104 to 105 per gram in two other samples. Examination of feed-grade frozen liver indicated the presence of 103 to 104 coagulase-positive staphylococci in one sample and 104 to 105 per gram in two samples.
DEVELOPMENT AND EVALUATION OF THE DIRECT MICROSCOPIC SOMATIC CELL COUNT (DMSCC) IN MILK1
Authors: Smith J. W.
Published: December 2016

The Direct Microscopic Somatic Cell Count (DMSCC) was evaluated in two counting trials. The within film variance was found to be 130% of the mean and the film component of variance was 15% of the mean. These statistics were used to estimate the expected precision of the method. These estimates should be used as guidelines by users until sufficient data is collected to allow reliable estimates for a particular laboratory. Constant reevaluation of the precision achieved in a laboratory can indicate areas of laxity in execution of laboratory procedures.