A CONVENIENT PLATINUM-WOUND RESISTANCE FURNACE1

Details of construction of the furnace are given including the principal platinum resistor, the two end coils, Chromel booster coil, shell, refractories, insulators, etc., with detailed drawings and photographs. The log and graphs showing the behavior of the furnace in cone 20 firing (1533°C) at rate of temperature increase of about 33°C per hour are given. The cost of the furnace, the controlling apparatus, and the temperature measuring equipment, are given in detail. The furnace meets the requirements successfully, as to performance. Its practical value will depend on the life of the platinum resistor which cannot be foretold. In the thirty-one firings so far completed no changes have been observed in the electric performance or apparent condition of the furnace. Its performance at the end of the first year's operation will be given in subsequent paper.     

Fertility in estrus-cycling and noncycling virgin heifers and suckled beef cows after induced ovulation

A procedure was developed to either induce or synchronize ovulation in heifers and suckled cows. Beef females were assigned to two breeding programs: 1) two injections of prostaglandin F2alpha (PGF2alpha) given 14 d apart to synchronize estrus (PGF2alpha control; n = 179), with inseminations 12 to 16 h after detected estrus or at 80 h in the absence of estrus, or 2) two injections of PGF2alpha (d -14 and 0) plus 100 microg of GnRH on d -7 when 6 mg of norgestomet was implanted (PGF2alpha/NORG/GnRH treatment; n = 173). Implants were removed 24 h after the second PGF2alpha injection (d +1) and females were inseminated 12 to 16 h after detected estrus until 54 h after PGF2alpha. The remaining cattle were given a second 100-microg GnRH injection 54 h after PGF2alpha and inseminated 18 to 20 h later. Percentages of noncycling females with subsequently elevated progesterone (P4) on d 0 or +1 were not different between treatment groups (20.4 vs 25%), but conception rate was greater (P < .05) in noncycling treated females than in noncycling controls (55 vs 12.8%). Conception rates in cycling (59.2%) and noncycling (62.2%) treated females were similar to those in cycling controls (56.2%) but greater (P = .06) than those in noncycling controls (26.5%). Conception rates in treated females inseminated 12 to 16 h after detected estrus (63.1%) or at one fixed time (58.3%) were similar to those in controls inseminated 12 to 16 h after detected estrus (68.7%). This treatment procedure produced fertility after one timed insemination that was equal to controls inseminated after detected estrus and induced equally fertile ovulations in noncycling heifers and cows.     

Review of The newer therapies: A sourcebook.

Reviews the book, The newer therapies: A sourcebook by Lawrence Edwin Abt and Irving R. Stuart (1982). This volume seeks to present a representative sample of innovative psychotherapies through the writings of leading practitioners of the approaches. The 21 chapters are grouped into four sections: "Cognitive Therapies" (including a cognitive approach to hopelessness, meditation techniques, and ego-state therapy); "Therapy with Children" (including paraverbal therapy and theraplay); "Group Approaches" (including family, group, and network therapies); and "Adjuvant Therapies". The chapters generally provide a well-written and authoritative introduction to the therapy approach at hand. With concise delineations of the fundamental theoretical assumptions, illustrative and effective excerpts from therapy sessions, and select primary source references, the chapters are stimulating even to the sophisticated reader. With its well-written, wide-ranging, and stimulating content, this book is especially suited for use by graduate students, supervised groups, and the practicing clinician. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Incidence and toxin production ability of Escherichia coli O157:H7 isolated from cattle trucks

Twelve cattle trucks were analyzed for the presence of Escherichia coli O157:H7. Three of them had been washed prior to arrival, and the others had not. Seventy-five percent of the trailers were positive for the presence of this foodborne pathogen. A total of 54 cultures were isolated and identified as E. coli O157:H7, all from the trucks that had not been cleaned. Most of the cultures (96.4%) produced Shiga-like toxin (verotoxin). No E. coli O157:H7 was detected in cattle trucks that were cleaned before arrival at the cattle pens. The incidence of E. coli O157:H7 in transport trailers increases the potential risk of contamination of cattle and transmission from farms to feedlots and to packing plants. This contamination increases the potential of contamination of meat during harvest and the risk of foodborne illnesses.     

Suspension properties of hexagonal BN powders: effect of pH and oxygen content

Suspension characteristics for two types (HCV and HCP) of hexagonal boron nitride (h-BN) powder have been examined and correlated to the amount of boric oxide present (B₂O₃) on the BN surface. The effects of B₂O₃ on the suspension behavior of HCV-BN and HCP-BN were determined by measuring the zeta () potential and viscosity as a function of pH. Results indicate the poor suspension quality of HCV-BN powders is linked to the increased presence of B₂O₃ on the particle surface. Because of its weak ionization characteristics, B₂O₃ acts to prevent stable suspension formation by decreasing the double layer length, thereby lowering the barrier to agglomeration. Hence, as the amount of B₂O₃ increases on the HCV-BN powder surfaces, the stability decreases and the particles agglomerate, rapidly settling out of higher viscosity suspensions. In contrast, HCP-BN having less B₂O₃ on the powder surface, exhibits higher -potentials and increased stability against agglomeration. Therefore, HCP-BN forms suspensions of single, unagglomerated particles which are less viscous, settle at a slower rate and are more suitable for slip casting operations.     

FURTHER DATA ON OPERATING COST OF A PLATINUM-WOUND RESISTANCE FURNACE1

The results derived on the cost of operating a platinum-wound resistance furnace after one year's use, are presented.     

Pioneer Venus Orbiter Electron Temperature Probe

The Orbiter Electron Temperature Probe (OETP) instrumentation and measurement technique has been designed to perform in-situ measurements of electron temperature and electron and ion density in the ionosphere of Venus. Adaptive sweep voltage circuitry continuously tracks the changing electron temperature and spacecraft potential while auto-ranging electrometers adjust their gain in response to the changing plasma density. Control signals used in the instrument to achieve this automatic tracking provide a continuous monitor of the ionospheric parameters without telemetering each volt-ampere curve. Internal data storage permits high data rate sampling of selected raw characteristic curves for low rate transmission to Earth. These curves are used to verify or correct the inflight processed data. Sample in orbit measurements are presented to demonstrate insrument performance.     

Effects of propionibacteria and yeast culture fed to steers on nutrient intake and site and extent of digestion

The effects of feeding Propionibacterium strain P169 (P169), yeast culture (XPY), and their combination on nutrient intake, site and extent of digestion, and ruminal kinetics were evaluated in a completely randomized experimental design. Ruminally and duodenally cannulated Angus × Hereford steers (n = 12) were assigned to 1 of 4 treatments in each of 2 periods: 1) control, fed a sorghum silage-based total mixed ration; 2) P169, fed the control plus P169 (6 × 10¹¹ cfu/steer per d); 3) XPY, fed the control plus XPY (56 g/steer per d); and 4) P169 + XPY, fed the control plus P169 and XPY (at 6 × 10¹¹ cfu/steer per d and 56 g/steer per d, respectively). Each period lasted 21 d; d 1 to 15 were used for diet adaptation and d 16 to 21 were used for fecal, duodenal, ruminal, and blood sample collection. Steers were individually housed and fed. Feeding XPY tended to decrease intake of organic matter, acid detergent fiber, and N, and decreased intake of neutral detergent fiber. However, feeding XPY alone tended to increase total tract digestibility of organic matter, N, neutral detergent fiber, and acid detergent fiber. Ruminal digestibility, duodenal flow, microbial N synthesis, microbial efficiency, and fluid and particulate passage rates were not affected by dietary treatments. Feeding P169 tended to decrease molar proportion of acetate, increased molar proportion of propionate (by 9.7%), and tended to decrease acetate:propionate ratio compared with control steers. No other effects of XPY or P169 on ruminal fermentation were observed. Plasma glucose and insulin concentrations were not affected by dietary treatment. Our results suggest that feeding P169 alters ruminal metabolism toward increased propionate without affecting feed intake or ruminal kinetics, whereas feeding XPY alone tended to increase total tract digestibilities of nutrients.     

Effects of varying levels of duodenal or midjejunal glucose and 2-deoxyglucose infusion on small intestinal disappearance and net portal glucose flux in steers

Six crossbred steers (261 +/- 18 kg BW) fitted with hepatic portal, mesenteric venous and arterial catheters, and duodenal, midjejunal, and ileal cannulas were used in a replicated 3 x 3 Latin square design to determine the effect of varying levels and site of glucose plus 2-deoxyglucose (2DG) infusion on net portal-drained visceral flux. Steers were fed chopped alfalfa in six equal portions daily at 1.5% of BW. Glucose (0, 9, or 18 g/h) and 2DG (0, 1, or 2 g/h) were infused continuously through the duodenal or midjejunal cannula (two infusion sites) at total glucose plus 2DG infusion rates of 0, 10, or 20 g/h. Arterial and portal blood samples were taken simultaneously at 20-min intervals from 5 to 9 h of infusion. Portal blood flow was determined by continuous infusion of p-aminohippurate and net flux was calculated as venous-arterial concentration (PA) difference times blood flow. Arterial concentration of glucose was not affected (P > .10) by glucose plus 2DG infusion, whereas arterial concentration of 2DG was greater (P < .05) when glucose plus 2DG was infused into the duodenum and increased (linear, P < .10) as amount of glucose plus 2DG infused into both the duodenum and midjejunum increased. Net portal flux and PA difference of glucose and 2DG were greater (P < .05) when glucose plus 2DG was infused into the duodenum. Although 2DG was infused at 10% of the total glucose plus 2DG infusion, it accounted for only 1.7 and .7% of the glucose plus 2DG appearing in portal blood when glucose plus 2DG was infused at 10 and 20 g/h, respectively. We conclude that glucose is more readily absorbed across the proximal-half than the distal-half of the small intestine, and that passive diffusion is a minor route of glucose absorption.     

THE INFLUENCE OF DIFFERENT FELDSPARS ON THE “FREEZING” BEHAVIOR OF CONES1

The term “freezing,” in ceramic parlance, means the increased resistance to viscous fusion, which ceramic bodies often show when their heat treatment is interrupted by chilling or the temperature is held static too long and not allowed to progress upward at the usual or proper rate. A body so treated often becomes distinctly more refractory and cannot be softened to viscous fusion without use of a higher temperature than would otherwise have been necessary. In this condition, it is said to be “frozen.” This freezing behavior may occur in the firing of cones as in other ceramic products, and, because of the use to which they are put and their shape which facilitates accurate comparisons, is more serious in its consequences and more easily detected than in other ceramic products. The present study was undertaken (a) to get some definite quantitative measurements of just what this lag in fusion amounts to under a given set of conditions, (b) to determine whether it is a peculiarity due to some one ingredient or combination of ingredients, or whether it is a generic quality applying to all ceramic mixtures of a given range, and (c) to get any new light that could be had as to the ultimate nature or cause of the phenomenon. The amount of the lag has been quantitatively determined for cone 10 as furnished by the Germans and our own factory, and the influence of different feldspars and clays in producing this lag has been experimentally studied. Different feldspars are shown to produce characteristic effects. No important light is thrown upon the ultimate cause of the phenomenon.