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Climate change remains a major topic of global concern in the twenty-first century. Recent research in this area has been focused on managing its impact and halting the increase of anthropogenic atmospheric greenhouse gases (GHGs). The construction and waste management industries remain one of the important players in the production of GHGs. Research works involving the calcination of eggshells has often been done by burning both shell and its constituent proteins and membrane. In the pursuit of a circular economy, this research investigated the effect of membrane separation on the calcination process and quality of CaO produced. Acetic and nitric acid was used to leach the eggshells and aid separation of the shell membrane. XRD, XRF, AA, and RGB analysis were used to characterize the calcined shells and leachate. Leaching was optimum at 60 minutes and averaged at 17 minutes. Optimum calcination occurred at 900°c. Leached and separated shells produced higher calcium concentration and crystallinity after calcination. Leaching duration beyond 17 minutes did not affect calcium content of the calcined shells as seen in the XRF results, however, XRD peaks of CaO experienced a reduction after 17 minutes of leaching. AA analysis also indicates that nitric acid dissolved more Ca during leaching. [ABSTRACT FROM AUTHOR]

The incidence and causes of children's accidents in the home are briefly described. Data on the most common types and locations of such accidents are provided in tables. Characteristics of children and the home environment that contribute to accidents are briefly discussed. In conclusion, problems associated with accident prevention strategies, such as preventive home design and safety education, are discussed. (Author/RH)

Of 25 western countries under consideration in 1975, Canada had the worst accident record for female children and the second worst for male children. In response to this problem, the present report assembles data to present a clearer picture of the extent of the problem and begins an analysis of potential accident events as a preliminary step to formulating plans for preventive action. The view is expressed that current prevention strategies have not been applied properly, consistently, or to their full extent. Responsibilities for effective intervention are discussed, including safety training for children at home, parental and community responsibilities, and responsibilities of regulatory and consumer protection organizations. Concluding remarks point out that other industrialized countries have achieved notable success in solving problems of child safety and suggest that Canadians appropriate safety technology and evaluate safety regulations. (RH)

In 2015 Applied Research Associates, Inc. (ARA) developed a virtual Roadway Weather Information System (vRWIS) that provides roadway maintenance staff with both current and forecasted roadway icing and freeze-thaw conditions. This virtual system uses a computerized climatic model which has evolved over the past 40+ years and can accurately predict the temperature in pavement systems based on atmospheric weather data inputs and pavement materials. Historically, the enhanced integrated climatic model (EICM) has been used for pavement performance research and as a key component in pavement performance modeling and pavement design. The EICM is one of the key modules in the AASHTO Pavement-ME Design software, which is the commercial version of the Mechanistic Empirical Pavement Design Guide (MEPDG). This paper details the level of accuracy at which the default EICM input values for asphalt and concrete pavements predict pavement temperatures compared to the measured values from actual roadway weather information systems (RWIS) in Illinois. First, several vRWIS stations were created to represent the predicted model. The process for creating a vRWIS station consists of collecting pavement structural and material information and then modeling the pavements at these locations with actual atmospheric weather data. Next, the difference between actual and modeled pavement temperatures was evaluated. The analysis determined that the default values in the EICM can accurately predict pavement temperature data. The one-to-one comparison shows an R2 above 0.85 for all selected sites. An additional finding concludes that the predicted model for the vRWIS site is more accurate at colder temperatures. The accuracy at colder temperatures is important for the vRWIS icing and freeze-thaw predictions, allowing winter maintenance crews to effectively determine when and where to use valuable labor and material resources. [ABSTRACT FROM AUTHOR]

The Cryogenic Dark Matter Search (CDMS) uses ultrapure germanium detectors at a temperature of approximately 40 mK. These detectors are maintained in a state where shallow impurities are well neutralized. Free electrons and holes, generated by particle events, are “hot” and remain out of equilibrium in the bulk. In this system, carrier drift and diffusion occur simultaneously with the generation of free carriers, and with recombination to localized bulk and surface states. These processes jointly affect the space charge distribution in the bulk and at the surfaces of our detectors. The impact of space charge on the electric field likely accounts for much of the phenomenology found in our detectors. Any ability to predict the evolution of the space charge distribution requires a fundamental understanding of carrier transport processes under our operating conditions. To this end, we have measured carrier drift velocities as a function of electric field in an high-purity CDMS detector of germanium <100> at a temperature of 31 mK. We adapted CDMS electronics to perform a high-bandwidth measurement of charge propagation times for near-surface events in our detector under test. We find that measured velocities coincide reasonably well with predictions made in our previous theory treatment. This indicates that carrier mobility is limited solely by phonon emission. [ABSTRACT FROM AUTHOR]

To optimize the signal efficiency in detectors utilizing Transition Edge Sensor (TES) technology we have fabricated and characterized test devices which approximate the electrical and thermal properties of the tungsten TES parallel arrays used for the Cryogenic Dark Matter Search (CDMS) phonon sensors. We measure the equilibrium power as a function of bias voltage by sweeping the bias current through the TES array and measuring the resulting current through the sensor. Our results are in agreement with previous estimates of the critical length for a TES to separate into superconducting and normal phases. However, we found that the presence of the tungsten sections, which connect the TES to the aluminum fins, significantly shortens the critical length for the onset of phase separation, and indicate that many CDMS phonon sensors have operated with phase separated TESs. We have also improved the determination of the electron-phonon coupling in our tungsten films to be (0.32±0.02)×109W/m3K5. Finally, we also found that the thermal conductance between the tungsten electron and phonon systems does not scale linearly with added fin connector volume, instead ∼75% of added volume contributes. [ABSTRACT FROM AUTHOR]

SuperCDMS employs 1-inch thick germanium crystals operated below 50mK in a dilution cryostat. Each detector produces ionization and phonon signals. Ionization signals are amplified by JFETs operating at 150K within an assembly mounted on the 4K cryostat stage. These high impedance signals are carried to the FETs by superconducting “vacuum coaxes” which minimize thermal conductivity, stray capacitance, and microphonics. Transition edge sensors produce low-impedance phonon signals, amplified by SQUID arrays mounted on a 600mK stage. Detectors are mounted in a six-sided wiring configuration called a “tower”, which carries signals from 40mK to 4K. A flex circuit 3 meters in length carries amplified signals for each detector from 4K to a vacuum bulkhead. We describe the methods used to support the detectors, wiring and amplifier elements at various thermal stages, minimizing electrical noise and thermal loads. [ABSTRACT FROM AUTHOR]

The Cryogenic Dark Matter Search experiment (CDMS) is using Phonon+Ionization detectors to search for Dark Matter in the form of Weakly Interactive Massive Particles (WIMPs). We report on new results from the operation of CDMS five “towers” at Soudan underground laboratory. With new and more massive detectors, SuperCDMS project has been started since March 2009. We report on the current status of SuperCDMS and its perspective. [ABSTRACT FROM AUTHOR]

The Cryogenic Dark Matter Search (CDMS) searches for Weakly Interacting Massive Particles (WIMPs) with cryogenic germanium particle detectors. These detectors discriminate between nuclear-recoil candidate and electron-recoil background events by collecting both phonon and ionization energy from interactions in the crystal. Incomplete ionization collection results in the largest background in the CDMS detectors as this causes electron-recoil background interactions to appear as false candidate events. Two primary causes of incomplete ionization collection are suface and bulk charge trapping. Recent work has been focused on reducing surface trapping through the modification of fabrication methods for future detectors. Analyzing data taken with test devices shows that hydrogen passivation of the amorphous silicon blocking layer does not reduce the effects of surface trapping. Other data shows that the iron-ion implantation used to lower the critical temperature of the tungsten transition-edge sensors increases surface trapping, causing a degradation of the ionization collection. Using selective implantation on future detectors may improve ionization collection for events near the phonon side detector surface. Bulk trapping is minimized by neutralizing ionized lattice impurities. Detector investigations at testing facilities and at the experimental site in Soudan, MN have provided methods to optimize the neutralization process and monitor running conditions to maintain maximal ionization collection. [ABSTRACT FROM AUTHOR]

A new method to study the origin of the dead-layer in ionization-phonon detectors was developed wherein the ionization is measured via a 25 micron gap between the collection electrodes and germanium absorber. Phonon signals are measured with small tungsten thermometers (Tc∼90 mK) varnished to the Ge substrates. The Ge samples were studied using collimated 241Am sources. With this geometry, different contributions to the “dead-layer” effect can be studied independently: Carrier back diffusion, trapping on surface states, Schottky barrier lowering, etc. [ABSTRACT FROM AUTHOR]

For its dark matter search the SuperCDMS collaboration has developed new Ge detectors using the same athermal phonon sensors and ionization measurement technology of CDMS II but with larger mass, superior sensor performance and increased fabrication efficiency. The improvements in fabrication are described, a comparison of CDMS II and SuperCDMS detector production yield is reported, and future scalability addressed. [ABSTRACT FROM AUTHOR]

Whiteflies resistance to insecticides is a constant threat to successful management of sticky cotton resulting from inadequate control of Bemisia whiteflies. A three-stage resistance management program was implemented in Arizona cotton following a severe whitefly resistance crisis in 1995. This program has been highly successful for seven years. Success has been fostered by intensive investments into improved whitefly sampling and treatment decisions, coupled with conservation of natural enemies. This latter component has hinged on limited, strategic use of two insect growth regulators in cotton, use of the neonicotinoid insecticide, imidacloprid, in vegetables and melons, and tactical deployment of non-pyrethroid and pyrethroid chemicals. Statewide monitoring of whitefly resistance to insecticides in cotton, melons and greenhouse crops has permitted annual assessments of the status of whitefly resistance management in Arizona. In this paper we summarize susceptibility of whitefly collecions made in cotton in the 2002 and 2003 seasons and discuss longer term trends in resistance development. No major problems regarding field performance of insecticides against whiteflies were observed or reported in 2002 or 2003. However, monitoring confirmed the early stages of evolution of resistance to pyriproxyfen (Knack®) and showed that whiteflies possessing this resistance could be detected in all cotton-producing areas of the state. Susceptibility to buprofezin (Applaud®/Courier®) has not changed significantly since 1997. Mean susceptibility to synergized pyrethroids (e.g., Danitol® + Orthene®) has increased strikingly on a statewide basis since 1995. However, 50 and 25% of cotton fields sampled in 2002 and 2003, respectively, had resistance levels expected to result in inadequate performance of synergized pyrethroid treatments. Whiteflies from throughout Arizona were highly susceptible to imidacloprid (Admire®/Provado®) and two other neonicotinoid insecticides, acetamiprid (Intruder®) and thiamethoxam (Actara®/Centric®/Platinum®). [ABSTRACT FROM AUTHOR]

Monitoring of Arizona pink bollworm (PBW), Pectinophora gossypiella, susceptibility to Bt toxin Cry1Ac has been conducted annually since 1997. PBW were collected from cotton fields located throughout the Southwest in 2002, cultured in the laboratory, and tested for susceptibility to Cry1Ac using diet-incorporation bioassays. A total of 13 collections from Arizona were successfully reared and bioassayed. Six California collections and one collection each from New Mexico and Texas were also tested. Laboratory selection of pink bollworm collected in Arizona in 1997 and exposed to Cry1Ac in diet produced a strain capable of survival on Bollgard cotton. Subsequent studies showed that 10 ug Cry1Ac/ml of insect diet was a reliable diagnostic concentration for detection of pink bollworm that were homozygous for resistance to Cry1Ac. On this basis, resistant PBW were detected in 2002 in only 2 out of 13 Arizona strains. The overall frequency of resistant PBW in 2002 strains tested from Arizona was 0.17% and ranged from 0.0 to 1.7%. One of six California collections evaluated had a single resistant survivor. No resistant pink bollworms were detected in the single New Mexico and Texas collections evaluated. Resistant PBW were significantly more abundant in Arizona in 2001 and 2002 than they were in 1998, 1999 or 2000. However, the frequency of resistant survivors in bioassays was low in 2001 and 2002, and markedly lower than in 1997. Field evaluations of efficacy of Bt cotton were conducted by the Arizona Cotton Research and Protection Council in adjacent pairs of Bt and non-Bt fields at 43 Arizona locations. Pink bollworms were found in an average of 23.3% of non-Bt bolls statewide. Bolls from Bt cotton fields yielded an average of 0.144% (range 0 to 1.300%) infested bolls. Of these, all but three of the pink bollworm recovered from plantings of Bt cotton were from bolls that tested negative for Cry1Ac. We conclude from these findings that there is no indication that pink bollworm resistance to Cry1Ac was a problem at the locations sampled in 2002. Furthermore, Bt cotton continued to exhibit exceptional field performance in Arizona. [ABSTRACT FROM AUTHOR]

The Cryogenic Dark Matter Search (CDMS) uses Ge and Si detectors to search for Weakly Interacting Massive Particles (WIMPs) via their elastic-scattering interaction with atomic nuclei. The present results from CDMS give limits on the spin-independent WIMP-nucleon elastic-scattering cross section that exclude previously unexplored parameter space above 10 GeV/c². The second phase of the CDMS experiment, scheduled to start in January 2002, is expected to improve on the present sensitivity by more than two orders of magnitude. [ABSTRACT FROM AUTHOR]

The Ge and Si detectors developed by the Cryogenic Dark Matter Search (CDMS) II experiment rely on the simultaneous detection of athermal phonons and ionization produced by interactions in the crystal. The athermal phonons provide both the total energy deposited in an interaction and the information about the position of the interaction. We describe extracting this information from the pulse shapes in the four phonon sensors. We present the result of measurements made on a Si detector from the first CDMS II production batch. We also investigate ways of using the event position information to extract further information about the phonon signal. © 2002 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The ZIP detectors deployed in the CDMS II experiment utilize phonon sensors comprising W Transition Edge Sensors (TESs). In order to ensure uniform collection of the athermal phonon signal the TESs are dispersed uniformly on one side of a 1 cm thick, 3 inch diameter, disk. Each quadrant contains 1036 TESs connected in parallel to one series-array SQUID amplifier. The initial superconducting transition temperatures of these TESs tend to be too high for our requirements, and substantial gradients make the operation of the detectors difficult. Hence our implementation of Fe-56 ion implantation, as reported at the previous LTD meeting, to reduce in a controlled manner the transition temperature. However, the successful implementation of this ion-implantation scheme requires accurate knowledge of the initial transition temperature of each TES in a given quadrant. We report on our approaches and techniques employed to address the issue of determining the initial Tc distribution. [ABSTRACT FROM AUTHOR]

We report on the latest results from the CDMS (cryogenic dark matter search) experiment. The experiment uses superconducting particle detectors, operated below 100 mK, to search for dark matter in the form of weakly interacting massive elementary particles or WIMPs. These detectors are either Si or Ge crystals, where the electron-hole production and the phonon production are measured for each event, allowing the discrimination of electron recoils (most backgrounds due to gammas and betas) from nuclear recoils (due to WIMPs and neutrons). We have recently reported new limits from the Stanford shallow site experiment (CDMS-I) which explore supersymmetric models where the lightest supersymmetric particle is often an excellent WIMP candidate. We will also report on the Soudan deep site facility for the CDMS-II experiment which is under construction, and on the status of the CDMS-II detector fabrication. [ABSTRACT FROM AUTHOR]