Search

There is evidence to suggest that clathrate hydrates have a significant effect on the surface geology of icy bodies in the Solar System. However the aqueous environments believed to be present on these bodies are likely to be saline rather than pure water. Laboratory work to underpin the properties of clathrates in such environments is lacking. We fill this gap by carrying out a laboratory investigation of the physical properties of CO$_2$ clathrates produced in weak aqueous solutions of MgSO$_4$. We use synchrotron X-ray powder diffraction to investigate clathrates formed at high CO$_2$ pressure in ice that has formed from aqueous solutions of MgSO$_4$. We measure the thermal expansion, density and dissociation properties of the clathrates under temperature conditions similar to those on icy Solar System bodies. We find that the sulphate solution inhibits the formation of clathrates by lowering their dissociation temperatures. Hysteresis is found in the thermal expansion coefficients as clathrates are cooled and heated; we attribute this to the presence of the salt in solution. The density derived from X-ray powder diffraction is temperature and pressure dependent. When comparing the density of CO$_2$ clathrates to that of the solution in which they formed, we conclude that they sink in the oceans in which they form. We also find that the polymorph of ice present at low temperatures is Ih rather than Ic, which we attribute to the presence of the MgSO$_4$. We 1) conclude that the clathrate density has implications for their behaviour in satellite oceans as their sinking and floating capabilities are temperature and pressure dependent, 2) conclude that the presence of MgSO$_4$ inhibits the formation of clathrates and in some cases may even affect their structure and 3) report the dominance of Ih throughout the experimental procedure despite Ic being the stable phase at low temperature., Accepted for publication by Astronomy and Astrophysics on 25 January 2017. Abstract truncated

Samples of amorphous MgSiO_3 annealed at temperature steps leading up to their crystallisation temperature show a rise in photoluminescence activity, peaking at ~450C. The photoluminescence band has a main peak at 595nm and a weaker peak at 624nm. We present laboratory data to show that the maximum in photoluminescence activity is related to substantial structural reordering that occurs within a relatively narrow temperature range. We attribute the origin of the photoluminescence to non-bridging oxygen hole centre defects, which form around ordered nano-sized domain structures as a result of the breakup of tetrahedral connectivity in the disordered inter-domain network, aided by the loss of bonded OH. These defects are removed as crystallisation progresses, resulting in the decrease and eventual loss of photoluminescence. Thermally processed hydrogenated amorphous silicate grains could therefore represent a potential carrier of extended red emission.

A bespoke capillary sample holder is described that attaches to the cold head of a commercially manufactured (PheniX) closed-cycle helium cryostat originally intended for flat-plate geometry. The new holder allows high-resolution synchrotron powder diffraction data to be collected from samples in Debye–Scherrer geometry over the temperature range 11–295 K. To demonstrate that high-quality powder data can be obtained using this new sample holder, structural refinement (Rietveld) and thermal expansion results measured from reference samples (Si and Al) are presented.

The objectives of this study were to examine the effects of feeding zinc-treated soybean meal (Zn-SBM) on ruminal fermentation patterns and duodenal AA flows in steers fed diets based on corn silage and corn. Six steers (385 kg) fitted with ruminal, duodenal, and ileal cannulas were used in a replicated 3 x 3 Latin square design experiment with 14-d periods. Diets were supplemented with solvent-extracted soybean meal (SBM), Zn-SBM, or a 50:50 combination (CP basis) of SBM:Zn-SBM. Ruminal escape N content of SBM and Zn-SBM were 30.0 and 57.0%, respectively, based on 12-h Dacron bag incubation. Protein sources provided approximately 30% of total CP in diets containing 12.6% CP (DM basis). Dry matter intake was equalized throughout the study at 2.2% of average initial BW. Total N flow at the duodenum was similar (P = .47) among treatments, but a trend (P = .15) for increased nonmicrobial N flow occurred when SBM and Zn-SBM were fed in combination. Micobial N flow and true efficiency of microbial CP synthesis were not affected by treatment (P = .87 and .37, respectively). Ruminal fermentation characteristics generally were unaffected (P > .10) by protein source. A positive quadratic response (P < .06) was observed for total and essential AA flows to the small intestine because flows of total and essential AA from ruminally undegraded dietary protein tended (P = .12) to increase when SBM and Zn-SBM were fed in combination. Absorption of AA from the small intestine also showed a positive quadratic (P < .06) response for SBM:Zn-SBM. Microbial AA flow to the small intestine was similar (P = .87) among treatments.(ABSTRACT TRUNCATED AT 250 WORDS)

The objective of this study was to examine the effect of combining ruminally degradable and undegradable CP sources on ruminal microbial protein synthesis and postruminal N and amino acid (AA) flows in steers. Six steers fitted with ruminal, duodenal, and ileal cannulas were fed diets containing corn silage and high-moisture corn supplemented with urea, soybean meal (SBM), dry corn gluten feed (DCGF), a combination of corn gluten meal and blood meal (CB), or SBM and DCGF in combination with CB. Estimated ruminal N escapes for SBM, DCGF, and CB were 32, 25, and 68%, respectively. Supplemental CP sources supplied 35 to 40% of diet CP (12.5% CP diets). Dry matter intake was adjusted to 2.3% of BW for each steer in each period. Total N flow at the duodenum decreased (P < .01) when the diet was supplemented with urea vs other proteins due to decreased (P < .01) flow of nonmicrobial N. However, microbial N and AA flows were greater (P < .05) for urea than for other protein supplements. Disappearance of OM and NDF in the stomach decreased (P < .07) or was numerically lower but nonmicrobial N at the duodenum increased (P < .08) as CB replaced SBM or DCGF in the diet. Protein source had little effect on ruminal fermentation characteristics except that ruminal ammonia N (NH3N) concentration was higher (P < .05) for urea than for other treatments. Total AA and essential AA flows to and disappearance from the small intestine increased (P < .06) as CB replaced DCGF. However, substituting CB for SBM had little effect on intestinal flows and disappearance of AA. These data suggest that source of ruminally degradable CP can influence the efficacy of feeding ruminally degradable and undegradable CP in combination. In general, source of supplemental CP had a greater effect on the quantity than on the profile of absorbable AA supplied to the duodenum.

1. Tucaresol (589C80; 4[2-formyl-3-hydroxyphenoxymethyl] benzoic acid) interacts stoichiometrically with haemoglobin to increase oxygen affinity. By decreasing the proportion of insoluble deoxy sickle haemoglobin at capillary oxygen concentrations, tucaresol may be of therapeutic benefit in sickle cell anaemia. 2. In this study, which involved the first administration to man, the pharmacokinetics and pharmacodynamics of tucaresol were studied in healthy male volunteers following oral doses of 200-3600 mg. 3. Peak drug concentrations in plasma and erythrocytes were linearly related to dose; mean (s.d.) values were 95.8 (26.1) and 1035 (67) micrograms ml-1, respectively, at the highest dose. Median tmax in plasma was 6.5 h and in erythrocytes 24.5 h, when approximately 60% of the administered dose was in the target tissue. Plasma drug concentrations fell biexponentially with commencement of the apparent terminal elimination phase at approximately 24 h. The terminal elimination half-life from plasma increased with dose (r = 0.77; P < 0.0001) from 133-190 h at 400 mg to a mean (s.d.) of 289 (30) h at 3600 mg. Erythrocyte drug concentrations declined mono-exponentially with a half-life that was always shorter than the apparent terminal half-life in plasma: overall mean (95% CI) of t1/2 erythrocyte/t1/2 plasma ratio was 0.57 (0.53, 0.61). The erythrocyte AUC/plasma AUC ratio increased with dose (r = 0.67; P < 0.001). 4. The proportion of haemoglobin modified to a form with high oxygen affinity (%MOD) increased in a dose-related manner above doses of 800 mg reaching 19-26% after the 3600 mg dose.(ABSTRACT TRUNCATED AT 250 WORDS)

The compounds (Ti1-xZrx) (HPO4)2·H2O (x = 0—1) are synthesized from aqueous solutions of TiCl4, ZrOCl2, and H3PO4 (autoclave, 150 °C, 7 d) and characterized by synchrotron powder XRD and pair distribution function analysis of high energy synchrotron X-ray total scattering data.

Anhydrides derived from tall oil fatty acids offer enhanced corrosion inhibition properties compared to traditional dimer/trimer acids. The chemistry of this intermediate, its use in corrosion inhibition for downhole applications, and the synthesis of novel oil- and water-soluble derivatives were studied.

The phase stability and compatibility of intermediate temperature solid oxide fuel cell (IT-SOFC) composite cathodes of lanthanum nickelate, La2NiO4+δ (LNO), and ceria-gadolinium oxide, Ce0.9Gd0.1O2−δ (CGO10), have been investigated by high resolution synchrotron X-ray diffraction (XRD). No reaction was observed between LNO and CGO10 at temperatures of up to 900 °C when the composite is open to an ambient air environment. However, in a sealed capillary environment the 50:50 wt% LNO:CGO10 composite undergoes a partially reversible reaction at temperatures of 750 °C and above, whereby LNO decomposes to La2O3 and Ni. Changes in the CGO10 Bragg peaks indicate that this component is actively involved in this process. This study shows that the phase stability of LNO:CGO10 composites is highly dependent on oxygen partial pressure. In addition, it is observed that ex-situXRD is insufficient to determine the presence of reactivity in composite cathodes and that high resolution in situXRD measurements are required to obtain details of the complexity of phase stability in SOFC composite cathodes.

The in vitro precipitation of the metastable CaCO3 phases aragonite and vaterite in the presence of leucine is investigated. Under normal conditions, the production of CaCO3 via the hydrolysis of urea method favours the formation of regular needle-like aragonite crystals, with very minor quantities of vaterite and calcite. However in the presence of leucine, aragonite forms highly branched structures and the vaterite yield is increased, forming flower-like clusters composed of nano-thin sheets. Both the degree of aragonite branching and the occurrence, regularity of shape and number of vaterite "petals" increases with leucine concentration. The two phases exhibit different variations in their crystallographic parameters with increasing concentration, while the molecular structure appears unaffected.

IN A previous paper on wood sugar molasses as a feedstuff for laying hens (Cooney and Parker, 1952) it was pointed out that cane and beet molasses have been accepted and used as an ingredient in livestock and poultry rations for a good many years. The review of literature indicated that these products could be fed up to ten percent of the chicken’s total ration. However, levels of five to seven percent of the total ration seemed to be more generally accepted. McGinnis, MacGregor and Carver (1948) were the first to report on the use of molasses prepared from wood waste in poultry rations. They fed levels of 0, 5, 10, 15, and 20 percent of this product to duplicate lots of one week old New Hampshire chicks over a three-week test period. From this work they concluded that wood sugar molasses could be used in chick rations at any …

CANE and beet molasses have been accepted and used as feedstuffs in live-stock rations for a number of years. Their basic nutritive value appears to be in their carbohydrate content. These products, however, are also reasonably good sources of such vitamins as biotin, pantothenic acid, pyridoxine, and niacin. Cane and beet molasses are comparatively high in mineral elements varying from 6 to 10 percent of the total weight. (Ewing, 1947; Morrison, 1948; Titus, 1949). Acceptance and use of molasses as a feed stuff for poultry have in general been slow. Winter (1929) reported results from feeding cane molasses to pullet and laying hens at 5, 10, and 15 percent levels. The product produced a mild laxative effect while feed intake and egg production were only slightly less than that obtained from the control birds. Mortality was reported to have been less in the lots fed molasses than in the controls. . . .

IT IS the purpose of this paper to report our findings on the use of supplementary methionine, grit and stabilized animal fat in improving the efficacy of barley in broiler rations. Considerable data are available on the comparative value of barley versus wheat or corn in chick rations. The earlier literature on this subject has been reviewed by Crampton (1936). In summary of these early observations and findings concerning the use of barley in chick rations, it would appear that barley, corn and wheat can be used interchangeably provided vitamin A is added to the diets containing barley or wheat. Little information is available, however, regarding the use of barley in high-efficiency broiler rations. On the basis of the productive energy values of Fraps (1946), barley is given a value of approximately 70% that of corn. Bearse (1952) has indicated that barley can replace up to 50% of the corn …

We have investigated the annealing of the oxygen donor in silicon in the temperature range 550–700 °C using Heatpulse lamp annealing in the time range of 1–1200 s. As‐grown silicon wafers can contain donors due to cooling through 450 °C as a part of the crystal growth process. A 1‐s anneal at 650 °C is sufficient to eliminate these donors completely. Intentionally created donors were annealed in order to determine reaction kinetics. A second‐order process involving the donor plus another species fits the data, with an Arrhenius behavior as a function of temperature. The activation energy for this process is 1.7 eV.

There are several reports that the presence of hard-shelled eggs in the uteri of chicken hens at the time of artificial insemination adversely affects fertilization (Moore and Byerly, 1942; Parker, 1945; Bornstein et al., 1960). More recent research indicates that fertility is impaired by the presence of a hard-shelled egg in the uterus only if A.I. is done within the last 3 or 4 hours prior to laying, and that hens laying within 1 or 2 hours prior to A.I. also have reduced fertility (Johnston and Parker, 1970; Hughes, 1970). This indicates that some factor other than the presence of a hard-shelled egg in the uterus or the act of oviposition per se is responsible for the decreased fertilization rate. Since neurohypophysial hormones are known to cause oviposition in hens and the blood level of vasotocin increases greatly shortly before oviposition (Douglas and Sturkie, 1964), it is conceivable that these hormones may affect fertilization of hens inseminated near the time of oviposition.…

To determine whether sterility of adult male chickens fed a diet high in linoleic acid and low in vitamin E was permanent or could be reversed by supple mental vitamin E, 3 groups of 8 White Leghorn males were fed for a 40-week experi mental period as follows: group 1, a high linoleic acid (7.3% )-high vitamin E (166.3 mg/kg) diet; group 2, a high linoleic acid-low vitamin E (4.3 mg/kg) diet; and group 3, treated as group 2 from zero to 28 weeks and as group 1 from 28 to 40 weeks. The following results were obtained: 1) The adverse effect of the high linoleic acidlow vitamin E diet on fertility and semen concentration was confirmed. 2) The addi tion of vitamin E to the high linoleic acid diet at 28 weeks restored fertility to the1 level obtained from males receiving vitamin E throughout the trial. 3) Semen concen tration was improved following the addition of vitamin E to the diet at 28 weeks. 4) No meaningful differences on semen volume, hatchability of fertile eggs, feed con sumption, mortality, or body and testes weights were observed with males fed the various diets. The results indicate that the low fertility and semen concentration of male chickens fed a diet high in linoleic acid but low in vitamin E are reversible fol lowing vitamin E supplementation. Arscott et al. (1) reported that adult White Leghorn male chickens fed a diet high in linoleic acid but low in vitamin E and ethoxyquin for a 25-week experimen tal period experienced low fertility and reduced semen concentration. When such diets were supplemented with vitamin E or ethoxyquin, no adverse effects were noted. Also a diet low in both linoleic acid and vitamin E did not appear detrimental. Increasing the number of sperm insemi nated from males receiving a diet high in linoleic acid and low in vitamin E failed to improve fertility. Information on the permanence of sterility was not obtained. Adamstone and Card (2) reported ste rility, as evidenced by testicular degenera tion, in male chickens after having been fed a vitamin E-deficient diet for a 2-year period. Although evidence for permanent sterility was not presented, the irreversible nature of sterility resulting from vitamin E-deficient diets for male chickens appears in the literature (3). In this respect, Evans and Burr (4) and Mason (5) have reported on the irreversibility of the steril ity observed in male rats fed diets deficient in vitamin E; however, Bryan and Mason (6) were unable to demonstrate testicular degeneration in male mice fed diets de ficient in vitamin E for 400 days. The per manence of the testicular degeneration noted with guinea pigs fed vitamin Edeficient diets (7) apparently is not known (8). It was the purpose of the present experi ment to determine whether supplemental vitamin E would reverse the sterility noted in male chickens fed a diet high in linoleic acid.

Adult male chickens were fed diets low in linoleic acid, vitamin E and ethoxyquin or high in linoleic acid with or without added vitamin E or ethoxyquin for 25 weeks. Fertilizing capacity and sperm concentration of semen were adversely affected with males fed the high linoleic acid diet without vitamin E or ethoxyquin. The addition of vitamin E or ethoxyquin to the high linoleic acid diet overcame these adverse effects. The low linoleic acid diet without vitamin E and ethoxyquin had no adverse effect on fertilizing capacity and concentration of semen. No differences were evident for males fed any of the diets as far as semen volume, hatchability of fertile eggs, body or testes weights or feed consumption were concerned. During the 26th and 27th weeks increasing the number of sperm inseminated failed to improve fertility of the males fed the diet high in linoleic acid without vitamin E. The results indicate that diets high in linoleic acid but without vitamin E affect fertilizing capac ity as well as the number of sperm produced. Adamstone and Card ( 1) reported testicular degeneration resulting after a vita min E-deficient diet was fed to Rhode Island Red males for a 2-year period. Al though no differences were observed at one year, an adverse effect on fertilizing capacity was noted with a limited number of males after 2 years. More recently Machlin et al. (2) reported adverse effects on fertility as well as egg production of White Leghorn layers fed diets low in vitamin E but containing a high level of linoleic acid. They showed that lowered fertility and egg production were overcome by addition of vitamin E or ethoxyquin to the diet. In the absence of the high level of linoleic acid as well as vitamin E and ethoxyquin no adverse effects on fertility or egg production could be observed during the 6 weeks of their experiment. The relationship of vitamin E to linoleic acid metabolism has been reviewed by Scott (3). Evidence is cited indicating that vitamin E functions as a biological antioxidant that protects against encephalomalacia in chicks by preventing the breakdown of linoleic acid to 12-oxo-cis-9-octadecenoic (keto) acid. Whether or not the same relationship exists with adult poultry has not been established, but the data re ported with layers (2) suggest such a pos sibility. In view of a previous interest in the area of nutrition as related to male fertility (4), the present experiment was undertaken to determine whether linoleic acid would ex ert a detrimental effect on fertilizing ca pacity of adult male chickens fed diets with or without vitamin E or ethoxyquin.