scholarly journals A Cappable Almost Everywhere Dominating Computably Enumerable Degree

2007 ◽  
Vol 167 ◽  
pp. 17-31 ◽  
Author(s):  
George Barmpalias ◽  
Antonio Montalbán

2008 ◽  
Vol 73 (4) ◽  
pp. 1373-1388
Author(s):  
Rachel Epstein

AbstractWe examine the computably enumerable (c.e.) degrees of prime models of complete atomic decidable (CAD) theories. A structure has degree d if d is the degree of its elementary diagram. We show that if a CAD theory T has a prime model of c.e. degree c, then T has a prime model of strictly lower c.e. degree b, where, in addition, b is low (b′ = 0′), This extends Csima's result that every CAD theory has a low prime model. We also prove a density result for c.e. degrees of prime models. In particular, if c and d are c.e. degrees with d < c and c not low2 (c″ > 0″), then for any CAD theory T, there exists a c.e. degree b with d < b < c such that T has a prime model of degree b, where b can be chosen so that b′ is any degree c.e. in c with d′ ≤ b′. As a corollary, we show that for any degree c with 0 < c < 0′, every CAD theory has a prime model of low c.e. degree incomparable with c. We show also that every CAD theory has prime models of low c.e. degree that form a minimal pair, extending another result of Csima. We then discuss how these results apply to homogeneous models.



2002 ◽  
Vol 67 (4) ◽  
pp. 1579-1580
Author(s):  
Rodney G. Downey ◽  
Steffen Lempp

A computably enumerable Turing degree a is called contiguous iff it contains only a single computably enumerable weak truth table degree (Ladner and Sasso [2]). In [1], the authors proved that a nonzero computably enumerable degree a is contiguous iff it is locally distributive, that is, for all a1, a2, c with a1 ∪a2 = a and c ≤ a, there exist ci, ≤ ai with c1 ∪ c2 = c.To do this we supposed that W was a computably enumerable set and ∪ a computably set with a Turing functional Φ such that ΦW = U. Then we constructed computably enumerable sets A0, A1 and B together with functionals Γ0, Γ1, Γ, and Δ so thatand so as to satisfy all the requirements below.That is, we built a degree-theoretical splitting A0, A1 of W and a set B ≤TW such that if we cannot beat all possible degree-theoretical splittings V0, V1 of B then we were able to witness the fact that U ≤WW (via Λ).After the proof it was observed that the set U of the proof (page 1222, paragraph 4) needed only to be Δ20. It was then claimed that a consequence to the proof was that every contiguous computably enumerable degree was, in fact, strongly contiguous, in the sense that all (not necessarily computably enumerable) sets of the degree had the same weak truth table degree.



Author(s):  
A.K. Rai ◽  
A.K. Petford-Long ◽  
A. Ezis ◽  
D.W. Langer

Considerable amount of work has been done in studying the relationship between the contact resistance and the microstructure of the Au-Ge-Ni based ohmic contacts to n-GaAs. It has been found that the lower contact resistivity is due to the presence of Ge rich and Au free regions (good contact area) in contact with GaAs. Thus in order to obtain an ohmic contact with lower contact resistance one should obtain a uniformly alloyed region of good contact areas almost everywhere. This can possibly be accomplished by utilizing various alloying schemes. In this work microstructural characterization, employing TEM techniques, of the sequentially deposited Au-Ge-Ni based ohmic contact to the MODFET device is presented.The substrate used in the present work consists of 1 μm thick buffer layer of GaAs grown on a semi-insulating GaAs substrate followed by a 25 Å spacer layer of undoped AlGaAs.



2018 ◽  
Vol 2 (1) ◽  
pp. 43
Author(s):  
Suwignyo Suwignyo ◽  
Abdul Rachim ◽  
Arizal Sapitri

Ice is a water that cooled below 0 °C and used for complement in drink. Ice can be found almost everywhere, including in the Wahid Hasyim Sempaja Roadside. From the preliminary test, obtained 5 samples ice cube were contaminated by Escherichia coli. The purpose of this study was to determine relationship between hygiene and sanitation with presence of Eschericia coli in ice cube of home industry at Wahid Hasyim Roadside Samarinda. This research used quantitative with survey methode. The population in this study was all of the seller in 2nd Wahid Hasyim Roadside. Sample was taken by Krejcie and Morgan so the there were 44 samples and used Cluster Random Sampling. The instruments are questionnaries, observation and laboratory test. Data analysis was carried out univariate and bivariate (using Fisher test p= 0.05). The conclusion of this study there are a relation between chosing raw material (p=0,03) and saving raw material (p=0,03) with presence of Eschericia coli. There was no relation between processing raw material into ice cube with presence of Eschericia coli (p=0,15).Advice that can be given to ice cube should maintain hygiene and sanitation of the selection, processing and storage of ice cube.



2017 ◽  
Author(s):  
Stephen J Choi ◽  
Gil-Lyeol Jeong ◽  
Hogun Park
Keyword(s):  


2021 ◽  
Vol 50 ◽  
pp. 16-33
Author(s):  
Meng Huang ◽  
Yi Rong ◽  
Yang Wang ◽  
Zhiqiang Xu


1983 ◽  
Vol 16 (3) ◽  
Author(s):  
Bozena Szkopińska ◽  
Janusz Jaskuła


2014 ◽  
Vol 12 (1) ◽  
pp. 148-158 ◽  
Author(s):  
AKM Mohiuddin ◽  
Manas Kanti Saha ◽  
Md Sanower Hossian ◽  
Aysha Ferdoushi

Banana (Musa paradisiaca) is one of the most important gigantic and oldest cultivated fruit crops grown almost everywhere in Bangladesh. Presently, the banana pseudostem is hazardous waste in Bangladesh whilst it has been used in several countries to develop important bio-products such as fibre to make yarn, fabric, apparel as well as fertilizer, fish feed, bio-chemicals, paper, handicrafts, pickles, candy, etc. Looking at this perspective, entrepreneurs of Bangladesh should take this golden opportunity and do the needful for such kind of business. The land of our country is suitable for banana production. Its fruit is a healthy diet and demandable in local markets as well as the free waste could be utilized to produce such bio-products which will contribute directly in our national economy. Thus, farmers or entrepreneurs should cultivate more banana trees in unproductive lands of coastal and hilly areas for extra income from the useless wastes and ensure eco-friendly environment. Women can also be employed in production of different bio-products from banana wastes and thus, they can contribute to their livelihood improvement. In conclusion, this review on banana waste utilization will be of help to the farmers, entrepreneurs, planners, scientists as well as Bangladesh government to take proper initiatives in socioeconomic improvement of Bangladesh. DOI: http://dx.doi.org/10.3329/agric.v12i1.19870 The Agriculturists 2014; 12(1) 148-158



2001 ◽  
Vol 66 (2) ◽  
pp. 873-880 ◽  
Author(s):  
Tamara J. Hummel ◽  
Carl G. Jockusch

AbstractIt is shown that for each computably enumerable set of n-element subsets of ω there is an infinite set A ⊆ ω such that either all n-element subsets of A are in or no n-element subsets of A are in . An analogous result is obtained with the requirement that A be replaced by the requirement that the jump of A be computable from 0(n). These results are best possible in various senses.



2015 ◽  
Vol 38 (3) ◽  
pp. 513-528 ◽  
Author(s):  
S. Fischler ◽  
M. Hussain ◽  
S. Kristensen ◽  
J. Levesley


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