An Interactive Dynamic Inventory-Production Control System

The development and evaluation of an interactive model for controlling inventories and scheduling production in a high technology batch production environment are discussed. The model allows the use of expert knowledge and company policy for matters such as customer service and safety stocks, in an interactive way. Production of a large number of products has to be scheduled for a number of time periods and a modified Wagner-Whitin algorithm is used for developing good schedules. A versatile data and information management system is a part of the developed software which has been implemented using a standard microcomputer. An evaluation suggests that the system is a practical one for use by busy managers. Further, it results in substantial cost savings and increased customer service.     

NMR relaxometry study of gelatin based low-calorie soft candies

ABSTRACT

Soft candies are popular confectionery products. The most significant concern on the consumption of these products is the high amount of sugar and thus the high calories. The use of low-calorie sweeteners is a desirable trend in confectionery research. In this study, gelatin-based soft candies were formulated by using different sweeteners and their characterisation was performed using high and low field nuclear magnetic resonance (NMR) relaxation experiments. To complement the information obtained by NMR experiments, moisture content, water activity, texture analysis and differential scanning calorimeter experiments were also conducted. T₁ and T₂ relaxation times were measured at both low and high fields and also temperature-dependent measurements were conducted at the high field system. Candies were formulated by substitution of sucrose with maltitol, isomalt and stevia at 30%, 50% and 70% ratios. Significant difference was observed on relaxation times. T₁ values were best described by a mono-exponential model, whereas for T₂ relaxation times a bi-exponential model gave better results at both fields.     

Efficient algorithms for tree reconstruction

In this note, we show thatO(n logn) operations are sufficient to reconstruct an ordered binary tree given its inorder traversal and either its preorder or postorder traversal. An alternative linear representation allows reconstruction usingO(n) operations.     

Determination of rare earth elements and thorium in britholite ore by energy dispersive X-ray fluorescence spectrometry

A radioisotope-excited X-ray fluorescence technique is applied for the determination of thorium and rare earth elements in britholite ore from Canada. An annular source of⁵⁷Co is employed for excitation of characteristic K X-rays of thorium and rare earth elements. The peak ratios of lanthanides were used to remove the difficulties because of overlapping lines at the 33–50 keV energy region. Matrix effects are examined also in detail and compensated for infinitely thick powdered ore sample. Results obtained in the analysis agree well with recommended values of Canada.     

Toughness enhancers for bone scaffold materials based on biocompatible photopolymers

Providing access to the benefits of additive manufacturing technologies in tissue engineering, vinyl esters recently came into view as appropriate replacements for (meth)acrylates as precursors for photopolymers. Their low cytotoxicity and good biocompatibility as well as favorable degradation behavior are their main assets. Suffering from rather poor mechanical properties, particularly in terms of toughness, several improvements have been made over the last years. Especially, thiol–ene chemistry has been investigated to overcome those shortcomings. In this study, we focused on additional means to further improve the toughness of an already established biocompatible vinyl ester‐thiol formulation, eligible for digital light processing‐based stereolithography. All molecules were based on poly(ε‐caprolactone) as building block and the formulations were tested regarding their reactivity and the resulting mechanical properties. They all performed well as toughness enhancer, ultimately doubling the impact resistance of the reference system. © 2018 The Authors. Journal of Polymer Science Part A: Polymer Chemistry published by Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 110–119     

Antimony and silicon environments in antimony silicate glasses

Antimony silicate glasses, of general formula xSb₂O₃·(1−x)SiO₂ (0.1≤x≤0.78), have been prepared by melt-quenching and their structures studied using ²⁹Si MAS NMR spectroscopy, ¹²¹Sb Mössbauer spectroscopy and Raman spectroscopy. Oxidation during melting gives rise to Sb⁵⁺ in concentrations, which increase linearly with x to give a value of ∼10% when x=0.78. ¹²¹Sb Mössbauer spectra show Mössbauer shifts and quadrupole splittings consistent with Sb³⁺ in a [:SbO₃] trigonal pyramid, similar to that in crystalline Sb₂O₃. A broad band in the Raman spectrum at ∼410 cm⁻¹ is due to the vibrations of such a unit. The dependence of the silicon Qⁿ speciation on x can be interpreted by the formation of Sb-O-Sb links possibly to form rings of 4 [:SbO₃] units such as are found in valentinite.     

Inversion layer plasma waves in quantizing magnetic field

The electromagnetic plasma wave spectrum of an inversion layer plasma subject to Landau quantization is investigated here. Magnetic field effects on local and nonlocal plasma modes are determined using the two dimensional RPA magnetoconductivity tensor.     

EM Heating-Stimulated Water Flooding for Medium–Heavy Oil Recovery

We report a study of heavy oil recovery by combined water flooding and electromagnetic (EM) heating at a frequency of 2.45 GHz used in domestic microwave ovens. A mathematical model describing this process was developed. Model equations were solved, and the solution is presented in an integral form for the one-dimensional case. Experiments consisting of water injection into Bentheimer sandstone cores, either fully water saturated or containing a model heavy oil, were also conducted, with and without EM heating. Model prediction was found to be in rather good agreement with experiments. EM energy was efficiently absorbed by water and, under dynamic conditions, was transported deep into the porous medium. The amount of EM energy absorbed increases with water saturation. Oil recovery by water flooding combined with EM heating was up to \(37.0\%\) larger than for cold water flooding. These observations indicate that EM heating induces an overall improvement in the mobility ratio between the displacing water and the displaced heavy oil.     

Functionalized 3(2H)-furanones via photooxygenation of (β-keto)-2-substituted furans: application to the biomimetic synthesis of merrekentrone C

Photooxygenation of (β-keto)-2-substituted furans leads, in a one pot operation, to functionalized 3(2H)-furanones with good to excellent yields. This methodology was applied as a key-step to the concise and biomimetic synthesis of the sesquiterpene merrekentrone C. The precursor to merrekentrone C, keto difuran, was synthesized using a cross coupling of α-iodo-3-acetylfuran with an alkenyl furan under Fenton-type conditions.