Eight new state records of aleyrodine whiteflies found in Clark County, Nevada and three newly described taxa (Hemiptera: Aleyrodidae, Aleyrodinae)

Eight new state records and the three newly described species are the subject of this publication. Whiteflies (Hemiptera: Sternorrhyncha: Aleyrodidae: Aleyrodinae) were collected from 2003 through 2009 within the Las Vegas area of Clark County, Nevada to determine the occurrence of newly established species and host range and distribution. Prior to 2003 the following ten whiteflies were known to be established in Nevada: Aleuroglandulus subtilis Bondar, Aleuroplatus berbericolus Quaintance and Baker, Aleyrodes spiraeoides Quaintance, Bemisia tabaci (Gennadius), Dialeurodes citri (Ashmead), Siphoninus phillyreae (Haliday), Tetraleurodes mori (Quaintance), Trialeurodes abutiloneus (Haldeman), Trialeurodes packardi (Morrill), and Trialeurodes vaporariorum (Westwood). Based on collections made after 2003, eleven additional whitefly species were found in Nevada. Of these the following eight were described species from California and other western U.S. states: Aleuroparadoxus arctostaphyli Russell, Aleuroplatus gelatinosus (Cockerell), Aleuropleurocelus ceanothi (Sampson), Aleuropleurocelus nigrans (Bemis), Tetraleurodes quercicola Nakahara, Trialeurodes corollis (Penny), Trialeurodes eriodictyonis Russell, and Trialeurodes glacialis (Bemis). Three new species are described and illustrated: Aleuropleurocelus nevadensis Dooley sp. nov., Tetraleurodes quercophyllae Dooley sp. nov., and Trialeurodes pseudoblongifoliae Dooley sp. nov

Band structure analysis of the conduction-band mass anisotropy in 6H and 4H SiC

The band structures of 6H and 4H SiC calculated by means of the FP-LMTO method are used to determine the effective mass tensors for their conduction-band minima. The results are shown to be consistent with recent optically detected cyclotron resonance measurements and predict an unusual band filling dependence for 6H-SiC.Comment: 5 pages including 4 postscript figures incorporated with epsfig figs. available as part 2: sicfig.uu self-extracting file to appear in Phys. Rev. B: Aug. 15 (Rapid Communications

Glaciological results of the 2005 expedition to Inylchek Glacier, Central Tian Shan

Like many other glaciers in Central Asia, Southern Inylchek glacier in the Kyrgyz Tian Shan is covered by supraglacial moraine, which drastically influences melt rates and complicates the estimation of ablation. The quantification of sub-debris melt from simple parameters is still an unsolved problem, but also essential to predict future yield from high mountains. Snow cover and glacier ice are the main water storages for the surrounding arid lowlands and a better understanding of ablation processes is the prerequisite for a sustainable water resources management. Another interesting feature of Southern Inylchek glacier is the existence of an ice dammed lake in a tributary valley, which is drained regularly by outburst floods. Improvements in predicting these floods would lower the risk potential for the downstream population. The main objectives of a group of glaciologists which participated in an expedition to the glacier in 2005 were to investigate melt rates on debris covered glacier parts and to quantify the ice flux into the glacier lake. The results of their field experiments are reported in this paper

The value of coordination in a two echelon supply chain: Sharing information, policies and parameters.

We study a coordination scheme in a two echelon supply chain. It involves sharing details of replenishment rules, lead-times, demand patterns and tuning the replenishment rules to exploit the supply chain's cost structure. We examine four different coordination strategies; naïve operation, local optimisation, global optimisation and altruistic behaviour on behalf of the retailer. We assume the retailer and the manufacturer use the Order-Up-To policy to determine replenishment orders and end consumers demand is a stationary i.i.d. random variable. We derive the variance of the retailer's order rate and inventory levels and the variance of the manufacturer's order rate and inventory levels. We initially assume that costs in the supply chain are directly proportional to these variances (and later the standard deviations) and investigate the options available to the supply chain members for minimising costs. Our results show that if the retailer takes responsibility for supply chain cost reduction and acts altruistically by dampening his order variability, then the performance enhancement is robust to both the actual costs in the supply chain and to a naïve or uncooperative manufacturer. Superior performance is achievable if firms coordinate their actions and if they find ways to re-allocate the supply chain gain.Bullwhip; Global optimisation; Inventory variance; Local optimisation; Supply chains; Studies; Coordination; Supply chain; IT; Replenishment rule; Rules; Demand; Patterns; Cost; Structure; Strategy; Retailer; Policy; Order; Variance; Inventory; Costs; Options; Variability; Performance; Performance enhancement; Firms;

Dampening variability by using smoothing replenishment rules.

A major cause of supply chain deficiencies is the bullwhip effect which can be substantial even over a single echelon. This effect refers to the tendency of the variance of the replenishment orders to increase as it moves up a supply chain. Supply chain managers experience this variance amplification in both inventory levels and replenishment orders. As a result, companies face shortages or bloated inventories, run-away transportation and warehousing costs and major production adjustment costs. In this article we analyse a major cause of the bullwhip effect and suggest a remedy. We focus on a smoothing replenishment rule that is able to reduce the bullwhip effect across a single echelon. In general, dampening variability in orders may have a negative impact on customer service due to inventory variance increases. We therefore quantify the variance of the net stock and compute the required safety stock as a function of the smoothing required. Our analysis shows that bullwhip can be satisfactorily managed without unduly increasing stock levels to maintain target fill rates.Bullwhip effect; Companies; Cost; Costs; Impact; Inventory; Managers; Order; Replenishment rule; Rules; Safety stock; Supply chain; Supply chain management; Variability; Variance; Variance reduction;

Smooth is smart: bullwhip, inventory, fill-rates and the golden ratio.

Inventory;

Second harmonic generation in SiC polytypes

LMTO calculations are presented for the frequency dependent second harmonic generation (SHG) in the polytypes 2H, 4H, 6H, 15R and 3C of SiC. All independent tensor components are calculated. The spectral features and the ratios of the 333 to 311 tensorial components are studied as a function of the degree of hexagonality. The relationship to the linear optical response and the underlying band structure are investigated. SHG is suggested to be a sensitive tool for investigating the near band edge interband excitations.Comment: 12 pages, 10 figure

Lateral Casimir-Polder force with corrugated surfaces

We derive the lateral Casimir-Polder force on a ground state atom on top of a corrugated surface, up to first order in the corrugation amplitude. Our calculation is based on the scattering approach, which takes into account nonspecular reflections and polarization mixing for electromagnetic quantum fluctuations impinging on real materials. We compare our first order exact result with two commonly used approximation methods. We show that the proximity force approximation (large corrugation wavelengths) overestimates the lateral force, while the pairwise summation approach underestimates it due to the non-additivity of dispersion forces. We argue that a frequency shift measurement for the dipolar lateral oscillations of cold atoms could provide a striking demonstration of nontrivial geometrical effects on the quantum vacuum.Comment: 12 pages, 6 figures, contribution to QFEXT07 proceeding