scholarly journals Drilling the new 5G-5 branch hole at Vostok Station for collecting a replicate core of old meteoric ice

2021 ◽  
pp. 1-6
Author(s):  
Aleksei V. Turkeev ◽  
Nikolai I. Vasilev ◽  
Vladimir Ya. Lipenkov ◽  
Alexey V. Bolshunov ◽  
Alexey A. Ekaykin ◽  
...  
Keyword(s):  
Performance Characteristics ◽  
Milling Cutter ◽  
Initial Design ◽  
Vostok Station ◽  
Cutter Head ◽  
The Voice

Abstract Recent studies have shown that stratigraphically disturbed meteoric ice bedded at Vostok Station between 3318 and 3539 m dates back to 1.2 Ma BP and possibly beyond. As part of the VOICE (Vostok Oldest Ice Challenge) initiative, a new deviation from parent hole 5G-1 was made at depths of 3270–3291 m in the 2018/19 austral season with the aim of obtaining a replicate core of the old ice. Sidetracking was initiated using the standard KEMS-132 electromechanical drill routinely employed for deep ice coring at Vostok, without significant changes to its initial design. Here we describe the method and operating procedures for replicate coring at a targeted depth in an existing slant hole, involving the use of a cable-suspended electromechanical drill. The design of the milling cutter head used for sidetracking is presented. The performance characteristics and the experience of drilling branch-hole 5G-5 at Vostok are described and discussed.

scholarly journals Special aspects of ice drilling and results of 5G hole drilling at Vostok station, Antarctica

2014 ◽  
Vol 55 (68) ◽  
pp. 173-178 ◽  
Author(s):  
V.S. Litvinenko ◽  
N.I. Vasiliev ◽  
V.Ya. Lipenkov ◽  
A.N. Dmitriev ◽  
A.V. Podoliak
Keyword(s):  
Drilling Fluid ◽  
Head Rotation ◽  
Hole Drilling ◽  
Circulation System ◽  
Drilling Process ◽  
Factors Affecting ◽  
Vostok Station ◽  
Extensive Experimental Data ◽  
Cutter Head ◽  
Hole Bottom

AbstractThis paper documents the drilling of the 5G deep hole at the Russian Vostok station, Antarctica. The hole construction is described and the specifications of the drill and surface drilling equipment are given. The peculiarities of drilling at various depths are considered. Based on the extensive experimental data collected at Vostok station, the processes occurring at the hole bottom are investigated: ice breaking and cutting, bottom cleaning and chip transport, and accumulation of the chips in the screen. The main factors affecting ice-drilling efficiency are the coarseness of ice crystals and the ice temperature. When ice crystal size exceeds 10 mm the cutting efficiency sharply decreases, and when ice temperature exceeds –5°C the chip transport from the hole bottom and the chip density in the screen are reduced. The drill advance then becomes irregular, slows down and may even be terminated in some cases. Optimal values of the basic drilling parameters (e.g. cutter head rotation rate and drilling fluid flow rate in the circulation system) have been deduced empirically. The designs of the cutter head and circulation system including screens have been significantly modified, allowing the drilling process to proceed at a normal rate even in the vicinity of the subglacial lake surface.

Public School Voice Clinics, Part I

1984 ◽  
Vol 15 (1) ◽  
pp. 51-57
Author(s):  
Sandra Q. Miller ◽  
Charles L. Madison
Keyword(s):  
Public School ◽  
School District ◽  
Voice Disorders ◽  
Urban School ◽  
Urban School District ◽  
Local School District ◽  
Local School ◽  
Perceived Need ◽  
The Voice ◽  
Voice Problem

The purpose of this article is to show how one urban school district dealt with a perceived need to improve its effectiveness in diagnosing and treating voice disorders. The local school district established semiannual voice clinics. Students aged 5-18 were referred, screened, and selected for the clinics if they appeared to have a chronic voice problem. The specific procedures used in setting up the voice clinics and the subsequent changes made over a 10-year period are presented.

Hormone Replacement Therapy and Voice

2019 ◽  
Vol 4 (4) ◽  
pp. 607-614
Author(s):  
Jean Abitbol
Keyword(s):  
Replacement Therapy ◽  
Symptom Severity ◽  
Low Dose ◽  
Hormone Replacement ◽  
Clinical Signs ◽  
Female Voice ◽  
Fat Cells ◽  
High Pitch ◽  
Endocrine Effects ◽  
The Voice

The purpose of this article is to update the management of the treatment of the female voice at perimenopause and menopause. Voice and hormones—these are 2 words that clash, meet, and harmonize. If we are to solve this inquiry, we shall inevitably have to understand the hormones, their impact, and the scars of time. The endocrine effects on laryngeal structures are numerous: The actions of estrogens and progesterone produce modification of glandular secretions. Low dose of androgens are secreted principally by the adrenal cortex, but they are also secreted by the ovaries. Their effect may increase the low pitch and decease the high pitch of the voice at menopause due to important diminution of estrogens and the privation of progesterone. The menopausal voice syndrome presents clinical signs, which we will describe. I consider menopausal patients to fit into 2 broad types: the “Modigliani” types, rather thin and slender with little adipose tissue, and the “Rubens” types, with a rounded figure with more fat cells. Androgen derivatives are transformed to estrogens in fat cells. Hormonal replacement therapy should be carefully considered in the context of premenopausal symptom severity as alternative medicine. Hippocrates: “Your diet is your first medicine.”

In the Limelight: The Voice Virtuoso

ASHA Leader ◽  
2014 ◽  
Vol 19 (2) ◽  
pp. 22-23
Author(s):  
Kellie Rowden-Racette
Keyword(s):  
The Voice

Modeling the Fundamental Frequency of the Voice

1982 ◽  
Vol 27 (9) ◽  
pp. 690-692 ◽  
Author(s):  
Janet Pierrehumbert ◽  
Mark Liberman
Keyword(s):  
Fundamental Frequency ◽  
The Voice
Sign in / Sign up

Export Citation Format

Share Document