Eigenstructure of distance matrices with an equal distance subset

We characterize the distance matrices with an equal distance subset in terms of eigenstructure and determine EDMs in this class by examination of a lower dimensional matrix.     

Reduced Load Equivalence under Subexponentiality

The stationary workload W _A+B ^φ of a queue with capacity φ loaded by two independent processes A and B is investigated. When the probability of load deviation in process A decays slower than both in B and $e^{ - \sqrt x } $ , we show that W _A+B ^φ is asymptotically equal to the reduced load queue W _A ^φ?b , where b is the mean rate of B. Given that this property does not hold when both processes have lighter than $e^{ - \sqrt x } $ deviation decay rates, our result establishes the criticality of $e^{ - \sqrt x } $ in the functional behavior of the workload distribution. Furthermore, using the same methodology, we show that under an equivalent set of conditions the results on sampling at subexponential times hold.     

Organizational Design of Post Corporation Structure Using Fuzzy Multicriteria Decision Making

A model for organizational design of post corporation structure is developed in this paper. Alternative organization solutions have been designed taking into account the post environment characterized by private operators' competition and development of new message transmission technologies. Criteria for organizational design have been considered as numerical and uncertain linguistic variables describes by fuzzy sets. The model has been tested on a numerical example.     

The molecular structure of trifluoroethene in the gas-phase as determined from electron diffraction and microwave data

The molecular structure of trifluoroethene was determined from electron diffraction data and the microwave rotational constants of the parent and deuterated molecule, corrected for zero-point vibrational motion. A GVFF adjusted to fit the vibrational frequencies was used for the correction. The molecule was found to be planar. Assuming equal geminal C1—F bond lengths, the following r_g distances and r_av angles are found: C1—F = 1.316 ± 0.011 Å, C2—F = 1.342 ± 0.024 Å, CC = 1.341 ± 0.012 Å, C—H = 1.100 ± 0.02 Å, ∠C—C—F1 = 123.1 ± 1.5°. ∠C—C—F2 = 124.0 ± 0.6°, ∠C—C—F3 = 120 ± 0.7° (Fl trans to F3) and ∠C—C—H = 124.0 ± 1.7°.The error limits include 3σ (σ = estimated standard deviation) and estimates of the systematic errors. The analysis suggests that all the C1—F distances are not equivalent, neither are the C2—C1—F angles, though the differences are not significant (10% level).     

Synthesis of novel analogues of 1alpha,25-dihydroxyvitamin D(3) with side chains at C-18

Novel analogues of the hormone 1alpha,25-(OH)(2)-D(3) with side chains attached to C-18 were synthesized by a versatile route in which key steps were the remote radical-induced functionalization of the 18-methyl by the C-8beta-hydroxyl group and the introduction of the side chains by Wittig reactions on a C-18-aldehyde. The triene system of the novel analogues was constructed by the convergent Lythgoe-Hoffmann la Roche approach, which involves reaction of a phosphine oxide (the ring A fragment) with a ketone (the upper fragment).     

Time-varying tandem queues with blocking: modeling,analysis, and operational insights via fluid models with reflection

In this paper, we develop time-varying fluid models for tandem networks with blocking. Beyond having their own intrinsic value, these mathematical models are also limits of corresponding many-server stochastic systems. We begin by analyzing a two-station tandem network with a general time-varying arrival rate, a finite waiting room before the first station, and no waiting room between the stations. In this model, customers that are referred from the first station to the second when the latter is saturated (blocked) are forced to wait in the first station while occupying a server there. The finite waiting room before the first station causes customer loss and, therefore, requires reflection analysis. We then specialize our model to a single station (many-server fluid limit of the \(G_t/M/N/(N +H)\) queue), generalize it to k stations in tandem, and allow finite internal waiting rooms. Our models yield operational insights into network performance, specifically on the effects of line length, bottleneck location, waiting room size, and the interaction among these effects.     

PHYTOCHROME CONTROL OF THE DEVELOPMENT OF PHOTOPHOSPHORYLATION

In the cotyledons of the mustard (Sinapis ah L.) seedling the development of the capacity for photophosphorylation is strongly influenced by pretreatment of the seedling with red light pulses. The red light acts through phytochrome. After a red light pretreatment the capacity for photophosphorylation increases linearly with the chlorophyll content, at least up to 30 min after the onset of continuous white light. It is proposed that the reaction chain required for photophosphorylation is completed under the influence of phytochrome even in the absence of chlorophyll. As soon as chlorophyll becomes available photophosphorylation functions instantaneously. Without a red light pretreatment there is a lag of more than 15 min before photophosphorylation becomes detectable after the onset of continuous white light even though chlorophyll a is available. Although phytochrome strongly influences the rate of chlorophyll accumulation as well it is improbable that the control by phytochrome of development of photophosphorylation and of chlorophyll accumulation are causally connected.     

Contamination of water and organic solvents stored in plastic bottles with phthalate ester plasticizers

Migration of phthalic acid esters into water, n-hexane, and methanol kept in polyethy-lene bottles or PVC tubes was investigated by high-performance liquid chromatography with a variable wavelength u.v. detector. The content of esters in water kept in contact with PVC for one day was 0.44 ppm and the migration rate of dibutyl phthalate was 4.8 × 10^-5 mg h^-1 cm^-2 of PVC tube. n-Hexane stored in a polyethylene bottle for 7 days contained 6 ppm esters; the migration rate of dibutyl phthalate was 6.4 × 10^-5 mg h^-1 cm^-2 of polyethylene. PVC tubing connected to ion-exchange resin columns contaminates deionized water with the esters.     

Population doses from terrestrial exposure in the vicinity of abandoned uranium mines in Serbia

A uranium mineralized area of Stara Planina Mt., Serbia, where uranium ore was exploited for seven years was characterized radiologically. Results were compared with those for an area of background radiation in the northern part of the mountain. The terrestrial gamma dose rate due to ²³⁸U, ²³²Th and ⁴⁰K in the area affected by mining activities was twofold higher than that of background area. The radiological situation of the affected area is not of immediate concern, except one location with elevated external hazard index where remediative measures taking into account site-specific ecological characteristics should be planned and implemented.