Optochemical Nanosensors and Subcellular Applications in Living Cells

 What may be the smallest anthropogenic devices to date, spherical sensors (wireless and fiberless) with radii as small as 10 nm have been produced. This class of optochemical PEBBLE (Probe Encapsulated By Biologically Localized Embedding) sensors covers a wide range of analytes (pH, calcium, oxygen and potassium included here) with excellent spatial, temporal and chemical resolution. Examples of such sensors for the monitoring of intracellular analytes are given. Methods, such as pico-injection, liposomal delivery and gene gun bombardment, are used to inject PEBBLE sensors into single cells. These PEBBLEs have caused minimal perturbation when delivered and operated inside single mammalian cells, such as human neuroblastoma, mouse oocytes or rat alveolar macrophage.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42448/1/604-131-1-2-121_91310121.pd

Lump-Sum Bonus Satisfaction: Testing the Construct Validity of a New Pay Satisfaction Dimension

There are both practical and theoretical reasons to measure lump-sum bonus satisfaction. The practical need for such a measure stems from its increased use as a component in modern compensation practices. Based on the means of administering and allocating lump-sum bonuses, a theoretical case can be built suggesting that lump-sum bonus satisfaction constitutes a separate component of pay satisfaction fitting into the Pay Satisfaction Questionaire\u27s (PSQ) theoretical framework. We develop 4 questions that complement the PSQ, and use a series of techniques to test the convergent and discriminant validity of the measure. Empirical evidence shows that bonus-related items are more related to the lump-sum bonus satisfaction measure than other PSQ dimensions. We also demonstrate that the dimension of lump-sum bonus satisfaction has a substantive relationship with attitudinal variables beyond that provided by pay level variables and the PSQ. The development of this measure should foster greater accuracy when assessing pay satisfaction levels and the effects of lump-sum bonus pay policies

Solvent extraction of zinc(II) ions from chloride media by 4-pyridylketoximes

Three homologues of 4-pyridylketoximes were synthesized and used as potential ligands for zinc(II). Their solvent extraction behaviors for zinc(II) in chloride solutions were investigated using CHCl3 as the diluent. The effect of different variables on the extraction of zinc(II) ions, such as the pH of aqueous phase, metal and chloride ions as well as the type of oxime, has been investigated. Results indicated that 4-pyridylketoximes could extract zinc(II) ions from chloride solutions and the extraction depended on the concentrations of the ligand, chloride ions and hydrochloride acid. Slope analysis confirmed that the 4-pyridylketoximes ligands form a 1:2 complex with zinc(II) in both chloride/nitrate and chloride/perchlorate solutions. After extraction, zinc(II) could be easily stripped from organic phase with water

Zwiększenie granicy stabilności w trakcie skrawania poprzez zastosowanie aktywnego uchwytu obróbkowego

In this paper the results of simulation of vibration suppression during machining are presented. Two versions of the active clamp system were examined. In the case when the work-piece vibration dominates one direction, the active clamp system with 1 degree of freedom (l-DOF) can be used. Also, a 2-DOF system is proposed to show the effectiveness of the active clamp system for a complex vibration scenario.W artykule przedstawiono koncepcję modyfikacji właściwości dynamicznych przedmiotu obrabianego poprzez zastosowanie aktywnego uchwytu mocującego. Zaletą prezentowanego rozwiązania, w porównaniu do innych metod, jest możliwość pracy z przedmiotami o dużej różnorodności. Ponadto, nie ma potrzeby wprowadzania dodatkowych modyfikacji w obrabianym przedmiocie. W pracy przedstawione zostały wyniki symulacji numerycznych ukazujące redukcję amplitudy drgań w trakcie obróbki dla dwóch wariantów konstrukcyjnych aktywnego uchwytu

Analiza aktywnej kontroli tłumienia drgań z zastosowaniem aktywnego narzędzia

The article represents a short overview of solutions available on the market, which allow for vibrations damping during the machining process. The description also provides information on the essence of chatter vibrations. The next part of the following paper includes the model of active machine tool based on piezoelectric actuator with work piece and the model of machining process. Next, the results of simulation research are presented for two control systems. All simulations were carried out in Matlab Simulink Software.Artykuł stanowi krótki przegląd rozwiązań dostępnych na rynku, pozwalających tłumić drgania w trakcie obróbki skrawaniem. W opisie można również znaleźć informacje dotyczące istoty drgań samowzbudnych. Kolejną cześć artykułu stanowi model aktywnego narzędzia na bazie piezoelektrycznego siłownika wraz z przedmiotem obrabianym oraz modelem procesu skrawania. Następnie zaprezentowane zostały wyniki badań symulacyjnych dla dwóch układów sterowania (LQG, LMS). Całość symulacji przeprowadzona została w środowisku Matlab Simulink

Charter suppression in machining

W celu zmniejszenia poziomu drgań podczas obróbki mechanicznej stosuje się eliminatory drgań. W artykule zaproponowano metody sterowania eliminatorem oparte na regule Internal Model Principle. Wykorzystano stacjonarny oraz adaptacyjny model zakłócenia. Algorytmy zostały porównane na drodze symulacji z metodą lokowania biegunów i zer oraz regulacją typu P.To alleviate the chatter problem in machining, vibration absorbes are used. In the paper IMP methods to control a semi-active vibration absorber with time-invariant and adaptive disturbances models are presented. The proposed methods are compared with suboptimal pole and zero placement and P control approach

Sensorless control scheme for teleoperation with force-feedback, based on a hydraulic servo-mechanism, theory and experiment

Telemanipulation systems with force-feedback are being developed from early 70's. These devices were successfully applied for remote manipulation of objects at very large distances. These types of manipulator systems are also applied in hostile environments. This work includes development of a new approach to a control design in bilateral teleoperation with force-feedback. The new control scheme does not require the force sensor placed between the manipulator body and objects of an environment. Presented approach estimates the value of environmental force impact on the manipulator body by an inverse mechanical model of the Slave subsystem. Prediction of the inverse model requires information about the value of current position of a manipulator joint. Presented system uses model estimated on-line, during manipulation tasks. Research was carried out on a hydraulic servo-mechanism test stand. The work ends with the report from the test stand and conclusions

Application of active eliminators if vibration in cutting process

W artykule przedstawiono dwie koncepcje sterowanych eliminatorów do redukcji drgań powstających przy frezowaniu. W obu konstrukcjach eliminatorów zastosowano siłowniki piezoelektryczne. Pierwsze rozwiązanie to eliminator dołączany do podatnego przedmiotu obrabianego. Do sterowania eliminatorem zastosowany został regulator LQG. Skuteczność proponowanego układu sterowania została potwierdzona doświadczalnie dla różnych parametrów skrawania. Zasadniczym problemem w stosowaniu tego typu rozwiązania jest konieczność przygotowania miejsca montażu eliminatora na obrabianym przedmiocie. Z tego względu rozpoczęto prace nad aktywnym uchwytem obróbkowym, który może być stosowany w przypadkach, gdy użycie eliminatora dołączanego do przedmiotu jest niemożliwe. W pracy przedstawiono model, syntezę układu regulacji oraz symulację pracy zaproponowanej konstrukcji.The paper presents two devices for controlling vibrations in the milling process. In both constructions piezoelectric actuators were used. In the first structure the eliminator was attached to the workpiece. To control the system a linear quadratic Gaussian (LQG) regulator was applied. The effectiveness of the eliminator was demonstrated in cutting experiments. The main problem that appears in this solution is the connection of the eliminator to the workpiece - in some cases such a connection is difficult to establish or is not even possible. The active workpiece holder system (active table) can be applied in a wider range of applications. The paper describes a mathematical model and synthesis of the control system. Efficiency of the proposed control method was examined by experiments and numerical simulations both for the workpiece eliminator and the active workpiece holder respectively