Mechanical, pH and Thermal Stability of Mesoporous Hydroxyapatite

The stability of mesoporous hydroxyapatite (HAP) powder was studied following treatments of ultrasound, pH and heating. HAP was found to be mechanically stable up to (and including) 1 h continuous ultrasonic treatment in water. The HAP structure was also stable to pH, evidenced by practically identical XRD and FTIR spectra over the pH range 2–12. The surface area increased progressively with increasing acidity, reaching a maximum of 121.9 m 2 g −1 at pH 2, while alkaline conditions decreased the surface area to a minimum of 55.4 m 2 g −1 at pH 12. Heating in air had a significant influence on the structural and morphological properties of HAP, which underwent dehydroxylation to form oxyhydroxyapatite (OHAP) at temperatures ≥ 650 °C, and β-tricalcium phosphate (β-TCP) ≥750 °C. The surface area decreased at elevated temperatures due to agglomeration of HAP crystals by sintering, which was associated with an increased particle size

Methane emission management in a dual-fuel engine exhaust using Pd and Ni hydroxyapatite catalysts

© 2017 Elsevier Ltd While dual-fuel engines reduce transportation costs and CO 2 emissions by using alternative energy sources e.g. natural gas, the exhaust streams often contain quantities of emissions that exceed limits and therefore require removal. Pd- and Ni-hydroxyapatite (HAP) catalysts were prepared using a soft-templating method and tested in the dry reforming of methane (DRM) in a fixed bed reactor that simulates an exhaust from a diesel-natural gas dual-fuel engine. XRD revealed the characteristic HAP crystal structure of all the prepared materials. The HAP phase was further confirmed by TEM, which also showed the presence of submicron sized particles. The BET surface areas of HAP prepared using a single surfactant was 27.7 m 2  g −1 and increased to 84.9 m 2  g −1 when mixed surfactants were used. Active metals were added to HAP using either incipient wetness impregnation, ion-exchange or solid dispersion. All the catalysts tested were active in DRM with the optimal samples converting over 85% of methane at 650 °C

Quality and Display Life of Carnation Blooms After Storage in Controlled Atmospheres

Report Summary: The quality of carnation blooms stored in 1/2 or 1 percent oxygen atmospheres was better after 4 to 5 weeks of storage than that of blooms held in air. Low-oxygen atmospheres reduced the incidence of decay in storage. However, the low-oxygen atmosphere in storage was only slightly effective in prolonging the display life. The addition of carbon dioxide to the low-oxygen atmospheres did not increase the storage life of the blooms. Carnation blooms held at 32° F. for 4 to 5 weeks developed petal injury. This injury was greatly reduced at 36°. Respiration rates during storage were reduced in low-oxygen atmospheres, but comparable increase in post-storage life of the blooms was not obtained

Improved Sulfur Dioxide Fumigation of Grapes Loaded in Railway Refrigerator Cars

Excerpts from the report: This report describes an important phase of the Department's research program on reducing post-harvest decay losses and maintaining quality in fresh table grapes. Effective fumigation of grapes in railroad refrigerator cars is necessary to prevent spoilage in transit and during marketing, and also to prevent injury to the fruit. All California and Arizona table grapes are fumigated with sulfur dioxide before shipment, to prevent decay. Improved methods of circulating the air in refrigerator cars to disperse the gas quickly and uniformly through the load are given in this report. If dispersal is slow or uneven, as is common in commercial practice, underexposure or overexposure results. Underexposure would allow decay to develop, and high concentrations of gas can severely damage the grapes

Commercial Packaging and Storing of Bare-Root Rose Bushes

Excerpts from the report Summary: Storage of year-old bare-root rose plants has been limited by the development of decay and loss of moisture in the plants. A new method of packaging that almost eliminates drying out has been developed and tested during 4 storage seasons. This method utilizes a polyethylene-coated kraft paper liner fitted into a carton, crate, or box. The use of cartons with the special liners would cut package costs about one-third as compared with costs of the conventional wirebound crate with waxed-paper lining and sphagnum moss and excelsior packing. The new method requires less labor to prepare the carton and liner for use than the old method; it reduces the weight of the packages by 20 percent, lowering the costs of shipping to eastern markets. Several fungicides were also tested. Decay in storage was controlled most consistently in these tests by dipping the bushes before packing into a suspension of 2 pounds of captan 50 WP in 100 gallons of water. This treatment not only reduced losses due to decay in storage but lessened the amount of labor required to recondition the bushes before planting. Other fungicides tested were somewhat less effective, while still others were either ineffective or harmful to the bushes

Modified Protective Services for Shipment of California Bartlett Pears -- Tests in 1960 Season

Excerpts from the report: Research in the 1959 season on modified icing for rail shipments of Bartlett pears suggested that one re-icing in transit would provide favorable temperatures for the initiation of ripening in early-season fruit. A series of shipping tests was conducted, therefore, to determine the relation of fruit maturity, initial fruit temperature, and modified icing practices to transit temperature and subsequent ripening of fruit at the market. New types of railway equipment with thermostatic temperature control required tests to determine their effectiveness in maintaining desired temperatures for Bartlett pears. Test shipments were made from the Sacramento River, Marysville, Placerville, and Lake County districts to the Chicago and New York marketing areas

Transit Times and Temperatures of Transcontinental Cut-Flower Shipments

Excerpts from the report: The test shipments were made under conditions that simulated commercial handling as closely as possible. Recording instruments and test bunches of flowers were placed in commercial packages at the packing plant and were recovered at the wholesalers. In most shipments, two recording thermometers were placed in each carton of flowers. One instrument was placed in the center of the package and the other at the end adjacent to the blooms. The condition of the flowers was evaluated at the destination by U. S. Department of Agriculture scientists who held the flowers to determine display life at temperatures commonly used by the trade