Search results for " Control"

Measurement of cloud point temperature in polymer solutions.

2013

A temperature-controlled turbidity measurement apparatus for the characterization of polymer solutions has been instrumented and set up. The main features are the coupled temperature-light transmittance measurement and the accurate temperature control, achieved by means of peltier cells. The apparatus allows to measure cloud point temperatures by adopting different cooling protocols: low rate for quasi-equilibrium measurements and high rate for detect kinetic effects. A ternary polymeric solution was adopted as case study system showing that cooling rate affects the measured cloud point temperature.

CHEMICAL INDUCTION OF PHYTOALEXIN SYNTHESIS IN GRAPEVINES: APPLICATION TO THE CONTROL OF GREY MOULD IN THE VINEYARD

2000

Dynamic optimization of a continuous Lactide ring-opening polymerization process

2019

An increasing attention has been paid to the production of the polylactic acid (PLA) in recent years, owing to its properties as a biodegradable thermoplastic besides the fact that it is derived from renewable resources. PLA is industrially produced by ring opening polymerization of lactide. This reaction is sensitive to deviations in the operating conditions that highly affect the reaction rate and the polymer properties. Therefore, a process monitoring and control policy is crucial in order to restore the nominal conditions in case of drift. In this paper, a continuous PLA process is considered with three cascade reactors, two tubular and one loop reactor, that is described by partial dif…

Design of the Biotechnological System for the Cultivation of a Polysaccharide-Producing Microorganism and Metabolites Separation

1970

This paper presents a design of the biotechnological system established for the cultivation of a polysaccharide-producing microorganism and the separation of the polysaccharide together with other metabolites. The strain used is a halophilic archaeon called Haloferax mediterranei (Mironescu et al., 2003). On designing the biotechnological system, some requirements are important: The recipients and the pipes must be resistant to the corrosion action of the cultivation substrate very rich in NaCl (125 to 150 g/l); A command and control system for pH, temperature and substrate and inoculum feeding is necessary; A system for monitoring dissolved oxygen and gases evacuated from the bioreactor (O…

Evidence of the Gluten-Free and Casein-Free Diet in Autism Spectrum Disorders

2014

In autism spectrum disorders, many parents resort to alternative treatments and these are generally perceived as risk free. Among these, the most commonly used is the gluten-free, casein-free diet. The objective of this work was to conduct a systematic review of studies published from 1970 to date related to the gluten-free, casein-free diet in autism spectrum disorder patients. Few studies can be regarded as providing sound scientific evidence since they were blinded randomized controlled trials, and even these were based on small sample sizes, reducing their validity. We observed that the evidence on this topic is currently limited and weak. We recommend that it should be only used after…

Zunehmende Bedeutung von Antidepressiva bei suizidalen und parasuizidalen Intoxikationen

2002

BACKGROUND AND OBJECTIVE: Antidepressant drugs are frequently used in deliberate self-poisoning resulting in a major risk for the patients due to their cardiac and central-nervous toxicity. In the present study the cases of intoxications consulting our Poison Center should be analysed illustrating recent results and trends about self-poisoning with antidepressants. PATIENTS AND METHODS: During the study period from 1995 to 2001 35 394 inquiries concerning deliberate self-poisoning were registered in our Poison Center. The substance used, age and gender of the patient as well as the degree of the observed symptoms were documented. Thereby, antidepressant drugs were grouped in tricyclic antid…

The Nonlocal Correlation Density Functional VV10

2015

Abstract In this chapter, we review the most relevant attempts to merge the Vydrov and van Voorhis nonlocal density-dependent functional kernel (VV10) with modern density functionals to accurately describe van der Waals interactions with a reasonable computational cost. The chapter is organized by providing first an introduction of the relevance of van der Waals interactions and the difficulties of common density functionals to describe these forces. Second, the historical developments that eventually give rise to the most modern formulation of the nonlocal density functional VV10 are briefly addressed. Then, an overview of its technical formulation, adjustable parameters, and implementatio…

Modification of Materials by MeV Ion Beams

2005

Today's fast developing technological based society places ever accelerating demands for new materials and materials processing methods. Leading edge fields as diverse as biomedical tissue engineering, quantum device, optical and magnetic information storage technology as well as immobilization of actinides, all require nanoscale engineering through controlled materials modification. The evolution of these advances from the research science stage to the industrial applications is a particular challenging task. Amongst the beam processing methods for materials modification MeV ions occupy a unique place. They interact strongly with both the atomic and electronic structures of the target mate…

ChemInform Abstract: Preparation of N,O-Aminals as Synthetic Equivalents of H2C=NAr and (H2C=NHAr)+ Ions: Neutral- and Acid-Promoted Transformations.

1988

A general method for the synthesis of N,O-aminals derived from primary aromatic amines is described. The reactivity of these compounds under neutral and acidic conditions has been studied and the title compounds can be envisaged as general purpose H2CNAr or (H2CNHAr)+ equivalents. N,O-Aminals have been converted into perhydrotriazines by moderate heating and into bis(4-aminoaryl)methane derivatives or N-benzylarylamines, respectively when heated in acidic media with pH control. Reduction of N,O-acetals with sodium cyanoborohydride has revealed that the C–O bond is broken exclusively in acidic media.

ChemInform Abstract: First Reactions of Dialkoxycarbenium Tetrafluoroborates with Pyrroles, 5H-Dibenz(b,f)azepines, and Electron-Rich Arenes.

1990

Pyrrole (2a) and 2,5-dimethylpyrrole (2b) react with the dialkoxycarbenium tetrafluoroborates 1a-1c under kinetic control to yield the corresponding acylpyrrole derivatives. 5H-Dibenz[b,f]azepine (9a) and the 10,11-dihydro derivative 9b react only with the most electrophilic of the series of electrophiles tested, namely, diethoxycarbenium tetrafluoroborate (1a), to furnish the corresponding formyl derivatives. Similarly, in arene chemistry, the highly electron-rich N,N-dimethylaniline (13a) and 1,3,5-trimethoxybenzene (13b) are formylated by reaction with 1a.